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The Opioid Crisis in Urology

The United States (U.S.) is currently in an opioid epidemic. Although the U.S. makes up only 4% of the global population, Americans consume 80% of worldwide opioids. Data from the U.S. National Institute on Drug Abuse indicates that 21-29% of patients prescribed opioids for chronic pain misuse them, and 8-12% of patients subsequently develop an opioid use disorder.1 Furthermore, an estimated 4-6% of patients who misuse an opioid prescription transition to heroin; 80% of people who use heroin first previously misused prescription opioids.1 Data from the CDC notes that 55% of patients that abuse opioids obtain them free from a friend or relative, while 17.3% of abusers obtained a prescription from a medical doctor. However, overprescribing of opioids is not a straightforward issue, as clinicians are faced with addressing acute postoperative pain, acute painful disease processes (ie. kidney stones), and chronic pain. This article will review the literature highlighting the opioid crisis in urology, assess non-opioid measures for pain control, and highlight prospective studies in an effort to stem the opioid crisis in urology.

The Opioid Crisis in Urology

A study in 2011 from the University of Utah provided surveys to consecutive patients undergoing surgery during a 3-month time frame to assess perception of pain control, type and quantity of medication prescribed, quantity of leftover medication, refills needed, disposal instructions, and surplus medication disposition.2 Surveys were performed 2 to 4 weeks postoperatively, and with the exception of the investigators, prescribing physicians had no prior knowledge of the study. Among the 586 patients undergoing surgery, 47% participated in the study. Hydrocodone was prescribed most commonly (63%), followed by oxycodone (35%); 86% of the patients were satisfied with pain control. Of the dispensed narcotics, only 58% were consumed, while 12% of patients requested refills. A total of 67% of patients had surplus medication from the initial prescription and an alarming 92% received no disposal instructions for surplus medication. Among patients with leftover medication, 91% kept the medication at home while 6% threw it in the trash, 2% flushed it down the toilet, and less than 1% returned it to a pharmacy. Indeed, the retained surplus of medication provides a readily available source of opioid excess.

In a prospective observational study of 155 opioid naïve patients who underwent a major prostate or kidney operation, investigators conducted a telephone survey 3-4 weeks postoperatively to assess the number of 5 mg oxycodone-equivalents prescribed, opioid use, and disposal.3 Most patients were male (86%), most were married (74%), the median was age 64 (IQR 59-70) years of age, and the majority were Caucasian (84%). Most patients reported social alcohol use (56%), but most denied current tobacco use (77%) or current and/or previous drug use (76%). Opioid prescribing exceeded use from 1.9- to 6.8-fold for all procedural categories. Overall, a total of 4,065 oxycodone-equivalents were prescribed during the study and 60% of pills prescribed went unused, resulting in 2,622 excess pills in the community.

Unfortunately, opioid overprescribing is not limited to the adult population, as it has also been demonstrated in pediatric urology patients. At the University of North Carolina, 117 pediatric urology patients’ parents were contacted with 39% completing a two-week post-operative telephone survey. The three most common pediatric urology procedures were inguinal hernia repair (n = 39), circumcision (n = 27), and cystoscopy (n = 16). Across all procedures, there was an average excess of 9.8 doses prescribed, corresponding to an over-prescription rate of 64%. Among the patients prescribed opioids, 41 (62%) had leftover opioid medication two weeks postoperatively. Thirty-two of 41 (78%) patients did not dispose of their leftover medication. Furthermore, only 13 patients received perioperative counseling on appropriate storage and disposal of opiates. A recent randomized control trial among 202 pediatric patients undergoing otolaryngologic or urologic procedures found that compared with providing only standard postoperative discharge instructions on opioid use, storage, and disposal, also providing a drug disposal bag significantly increased the rate of proper disposal of excess opioids by approximately 20%.4 These results suggest that a greater availability of disposal products may complement ongoing prescribing reduction efforts aimed at decreasing opioid misuse.

There are several reasons for the opioid crisis in urology, namely a culture of overprescribing.5 This may be due to:
  1. A historic failure to address acute pain in hospitalized patients, leading to the American Pain Society suggesting that pain should be akin to the fifth vital sign.6 Subsequently, physicians became more aware of their patients’ pain and were expected to treat their pain leading to an environment where liberal use of narcotics was tolerated.
  2. Over the past two decades, reimbursement, specifically through the Center for Medicare and Medicaid Services (CMS), has been linked to Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey. In the questionnaire, there were three questions dedicated to how well the patient’s pain was managed. These additional measures emphasizing the importance of pain management likely influenced the number of narcotics prescribed at discharge in order to maintain positive survey scores.
  3. Because narcotics must be prescribed via a hand-written prescription and obtaining additional pain medication is inconvenient for both patient and physician, providers may be more likely to overprescribe narcotics at discharge “just in case”.
The rates of opioid dependence and overdose after urological surgery are as follows:

table 1 opiods in urology2x

The American Urological Association’s (AUA) Quality Improvement Summit on Opioid Stewardship in Urology

The AUA Quality Improvement Summit took place at AUA headquarters in December 2018 and was divided into four sessions:
  • Session 1: Physician-led Multicomponent Interventions in Opioid Stewardship. Dr. Richard Barth discussed procedure-specific opioid prescribing guidelines, Dr. Jonah Stulberg discussed opioid reclamation efforts, and Dr. Jim Dupree presented the Michigan MUSIC initiative on opioid stewardship.
  • Session 2: Understanding Post-operative Pain. Dr. Brooke Chidgey discussed the pathophysiology of post-operative pain, Dr. Meghan Sperandeo-Fruge highlighted complementary alternative medicine pain management strategies, and Dr. Margaret Rukstalis discussed cognitive behavioral therapy and other non-pharmacologic approaches to pain management. In a sub-session discussing challenging cases in opioid management, Dr. Vernon Pais discussed the impact on prescription opioid use in patients with kidney stones, Dr. Matthew Nielsen highlighted the University of North Carolina Health Care System’s opioid stewardship program, and Dr. Benjamin Davies discussed his initiative of no opioids after a robotic prostatectomy.
  • Session 3: High-Risk Patients and Expectations. Dr. Behfar Ehdaie presented on the expectation setting for opioid prescribing, Dr. Margaret Rukstalis discussed a surgeon’s role in the management of opioid misuse disorders, and Dr. Brooke Chidgey discussed the role of pain specialists for managing high-risk patients.
  • Session 4: Policy and Outreach. Dr. Jennifer Waljee discussed opioid education and outreach, Dr. Scott Winiecki presented on opioid prescribing and the FDA safe use initiative, and Dr. Gregory Murphy completed the program discussing policy change and legislature to address the opioid crisis.

The full resources and slides for the AUA Quality Improvement Summit are available at: https://www.auanet.org/education/educational-calendar/quality-improvement-summit

Non-Opioid Measures for Pain Control

Data from Sweden suggests that opioid dependence may be specific to the U.S. Among 25,703 men in the National Prostate Cancer Register of Sweden who underwent radical prostatectomy, 16,368 men (64%) filled an opioid prescription during the 13 months before or after surgery.8 The use of strong opioids increased with time and the use of weak opioids decreased. There were 1.9% of men that had opioid prescriptions during the baseline period, followed by a spike to 59% around the time surgery, which sharply decreased by two months postoperatively. However, thereafter the proportion of men with opioid prescriptions remained slightly higher at 2.2% compared to the baseline before radical prostatectomy. Of chronic late users, 57% were previous users and 43% were new chronic users. Higher cancer risk category, greater comorbidity, unmarried status and low educational level were associated with the risk of new chronic opioid use. Although more than half of male Swedish patients filled an opioid prescription after radical prostatectomy, less than 1% of men became chronic opioid users.

Professor Benjamin Davies from the University of Pittsburgh has been a thought leader and advocate for minimizing opioid prescriptions among patients undergoing urologic procedures, namely advocating for the “No Opioid Robotic Radical Prostatectomy”.9,10 This protocol is as follows:
  • Pre-operative: Oral neurontin, acetaminophen, +/- celebrex
  • Quadratus lumborum block (ropivicaine, decadron, precedex)
  • Intraoperative: separate infusions of propofol, ketamine, and precede
  • Post-operative: Toradol 15 mg IV PRN while in the hospital
  • Tylenol and Motrin for 48 hours
Amid the opioid crisis, there has been an increased focus on increasing the use of regional anesthesia as part of opioid-sparing multimodal analgesia. Tranversus abdominis plane (TAP) block has been shown to improve early and late pain, and reduce opioid consumption after minimally surgery.11 These benefits have indirectly reduced the incidence of postoperative delirium, pneumonia, urinary retention, and falls. Furthermore, compared to epidural analgesia, a TAP block provides similar pain control, has a lower incidence of hypotension, and is associated with a shorter length of stay. A TAP block provides a safe intervention and should be integrated into enhanced recovery protocols for patients undergoing urologic procedures.

Prospective Initiatives

In an effort to evaluate the effect of opioid reduction after radical prostatectomy on post-discharge opioid prescribing, use, and disposal, the ORIOLES trial was designed as a prospective, non-randomized, pre-post interventional trial.12 An evidence-based intervention included a discharge sheet, nursing education, and standardized prescribing guideline; the primary outcome was total oral morphine equivalents used after surgery. Secondary outcomes included opioid prescribing, opioid disposal, need for additional opioid medication, and presence of incisional/post-surgical abdominal pain beyond 30-days. There were 214 men in the pre-intervention arm and 229 men in the post-intervention arm with 100% follow-up. The intervention reduced post-discharge opioid prescribing from 224.3 mg to 120.3 mg (p=0.01), reduced opioid use from 52.1mg to 38.3mg (p<0.01), and increased opioid disposal by 13.5% (p<0.01). Greater post-discharge opioid use was associated with greater prescribing of opioids at discharge, higher body mass index, and use of opioid medication prior to surgery.

From this prospective initiative, the authors demonstrate that a simple, three-component opioid reduction intervention was able to reduce opioid prescribing, reduce opioid use, and increase opioid disposal at 30-days after radical prostatectomy. Importantly, this prescribing guideline met the needs of 84% of patients, while only 2.2% of patients required additional opioid medication for pain. Furthermore, an impressive one-third of patients used no opioid pain medication after discharge.

Investigators from the Mount Sinai School of Medicine have also recently assessed the effect of implementing a nonopioid protocol for patients undergoing robotic-assisted radical cystectomy with extracorporeal urinary diversion.13 Among 52 patients undergoing surgery, patients received a multimodal pain management protocol, including a combination of nonopioid pain medications and regional anesthesia. These patients were compared to 41 patients undergoing robotic cystectomy prior to the implementation of the nonopioid protocol. In this study, the authors found that patients on the nonopioid protocol received a much lower dose of postoperative morphine milligram equivalents (2.5 vs. 44, p < 0.001), with no difference in pain scores. In the non-opioid protocol patients, the median time to regular diet was significantly shorter (4 days vs. 5 days, p = 0.002), and the length of stay was two days shorter compared to the control group (5 days vs. 7days, p < 0.001).

Conclusions

The urologic community has by no means been spared by the current opioid epidemic across the U.S. Several studies in both the adult and pediatric settings have demonstrated overprescribing measures with little to no counseling or options for appropriate disposal of opioids. Several measures are now in place to solve this problem5, including (i) greater utilization and implementation of Prescription Drug Monitoring Programs (PDMPs) to provide alerts to providers to patients who may be filling opiate prescriptions with multiple providers; (ii) CMS has removed the three questions from the HCAHPS survey related to pain control, effective January 2018; (iii) increased utilization of Enhanced Recovery After Surgery (ERAS) pathways as a measure for decreasing intra- and post-operative use of opioids; (iv) each of the 50 states have passed legislation to make readily available naloxone, which rapidly reverses the effects of opioids in the overdose setting; (v) the creation of procedure-specific guidelines for discharge opioid recommendations. For example, a Johns Hopkins expert panel assessing 20 common surgical procedures suggest that the ideal range of oxycodone 5-mg tablets prescribed to opioid naïve patients at discharge is 0-1014; (vi) the DEA sponsored “National Rx Takeback” initiative, providing collection sites (primarily pharmacies) for returning opioids. Certainly, the current opioid epidemic is multifactorial. However, judicious prescribing of opioids amongst the urology community is one actionable item that will make a difference for the betterment of our patients.

Published Date: December 2019 
Written by: Zachary Klaassen, MD, MSc
References: References:
1. National Institute on Drug Abuse. Opioid Crisis. 2017. Available at: www.drugabuse.gov/drugs-abuse/opioids/opioid-crisis
2. Bates C, Laciak R, Southwick A, Bishoff J. Overprescription of postoperative narcotics: a look at postoperative pain medication delivery, consumption and disposal in urological practice. J Urol. 2011;185(2):551-555.
3. Theisen KM, Myrga JM, Hale N, et al. Excessive Opioid Prescribing After Major Urologic Procedures. Urology. 2019;123:101-107.
4. Lawrence AE, Carsel AJ, Leonhart KL, et al. Effect of Drug Disposal Bag Provision on Proper Disposal of Unused Opioids by Families of Pediatric Surgical Patients: A Randomized Clinical Trial. JAMA Pediatr. 2019:e191695.
5. Theisen K, Jacobs B, Macleod L, Davies B. The United States opioid epidemic: a review of the surgeon's contribution to it and health policy initiatives. BJU Int. 2018;122(5):754-759.
6. Quality improvement guidelines for the treatment of acute pain and cancer pain. American Pain Society Quality of Care Committee. JAMA. 1995;274(23):1874-1880.
7. Shah AS, Blackwell RH, Kuo PC, Gupta GN. Rates and Risk Factors for Opioid Dependence and Overdose after Urological Surgery. J Urol. 2017;198(5):1130-1136.
8. Loeb S, Cazzaniga W, Robinson D, Garmo H, Stattin P. Opioid Use After Radical Prostatectomy: Nationwide, Population Based Study in Sweden. J Urol. 2019:101097JU0000000000000451.
9. Theisen KM, Davies BJ. A Radical Proposition: Opioid-sparing Prostatectomy. Eur Urol Focus. 2019.
10. Pekala KR, Jacobs BL, Davies BJ. The Shrinking Grey Zone of Postoperative Narcotics in the Midst of the Opioid Crisis: The No-opioid Urologist. Eur Urol Focus. 2019.
11. Shahait M, Lee DI. Application of TAP Block in Laparoscopic Urological Surgery: Current Status and Future Directions. Curr Urol Rep. 2019;20(5):20.
12. Patel HD, Faisal FA, Patel ND, et al. Effect of a Prospective Opioid Reduction Intervention on Opioid Prescribing and Use after Radical Prostatectomy: Results of the ORIOLES Initiative. BJU Int. 2019.
13. Audenet F, Attalla K, Giordano M, et al. Prospective implementation of a nonopioid protocol for patients undergoing robot-assisted radical cystectomy with extracorporeal urinary diversion. Urol Oncol. 2019;37(5):300 e317-300 e323.
14. Overton HN, Hanna MN, Bruhn WE, et al. Opioid-Prescribing Guidelines for Common Surgical Procedures: An Expert Panel Consensus. J Am Coll Surg. 2018;227(4):411-418.

First-line Treatment for Metastatic Castrate-resistant Prostate Cancer

In 2019 Prostate cancer (PCa) accounts for nearly 1 in 5 new diagnoses of cancer in men in the USA.1 In the last several years the overall prostate cancer (PCa) incidence rate declined by approximately 7% per year.1 The sharp drop in incidence has been commonly attributed to decreased prostate-specific antigen (PSA) testing from 2008 to 2013. The decreased use of PSA screening was caused by the United States (US) Preventive Services Task Force recommendations against routine PSA screening. This was a grade D recommendation specifically in men aged 75 years and older, which was declared in 2008, and later on expanded to all men in 2011, due to rising concerns of overdiagnosis and overtreatment.2 Although the prevalence of PSA testing stopped decreasing and stabilized from 2013 to 2015,3 the effect of screening reduction on the incidence of advanced disease is still unclear. An analysis of a large cancer registry covering 89% of the US population reported that the overall decline in PCa incidence is, in fact, masking an increase in distant-stage diagnoses from 2010 across age and race.4

Regardless of the treatment given, approximately 20%-30% of patients with localized PCa progress to metastatic disease, commonly treated with hormonal therapy.5 This can be given through surgical castration (bilateral orchiectomy) or through medical castration using androgen deprivation therapy (ADT). Both methods achieve a castrate level of serum testosterone which is regarded as the standard of care for treating metastatic hormone-sensitive PCa (mHSPC). However, mHSPC is destined to progress to metastatic castrate-resistant prostate cancer (mCRPC).6 The castrate-resistant prostate cancer (CRPC) state is defined as disease progression despite reaching castrate testosterone levels (serum testosterone < 50 ng/dL or 1.7 nmol/L), and can present as either a continuous rise in serum PSA levels, progression of pre-existing disease, and/or the appearance of new metastases.7 CRPC has a median survival of approximately three years8 and is associated with a significant deterioration of quality of life.9 The exact mechanism of transition from mHSPC to mCRPC is still unclear. However, it is known that despite castrate levels of androgens, the androgen receptor (AR) remains active and continues to drive PCa progression in CRPC.10 This has led to the development of novel agents aimed at further decreasing androgen production or blocking AR function. However, there are other biologic pathways that function independently of androgen signaling and also result in CRPC.

Several significant shifts have occurred in the treatment options of the mHSPC space resulting in substantial survival benefit (please see “The rapidly evolving management strategy of metastatic Hormone-Sensitive Prostate Cancer” link), including the introduction of chemotherapy in the CHAARTED study11 and STAMPEDE trial,12 the addition of abiraterone acetate and prednisone in the LATITUDE study13 and STAMPEDE trial,14 the addition of enzalutamide in the ARCHES trial15 and the ENZAMET study,16 and lastly, the addition of apalutamide, an oral nonsteroidal anti-androgen, which like enzalutamide, binds directly to the ligand-binding domain of the AR and prevents AR translocation, DNA binding, and AR-mediated transcription.17 The TITAN trial showed overall survival (OS) benefit in apalutamide-treated mHSPC patients.18 Apalutamide has also shown benefit over placebo in the non-metastatic CRPC (nmCRP) setting in the SPARTAN phase 3 placebo-controlled trial,19 similar to the benefit shown by enzalutamide-treated nonmetastatic castrate-resistant prostate cancer (nmCRPC) patients, in the PROSPER trial20 (please see “The novel treatments for the non-metastatic castrate-resistant prostate cancer” link). These treatment advances in the mHSPC and nmCRPC setting have raised the question of which treatment options should be offered to patients in the mCRPC setting.21

The treatment of men with CRPC has dramatically changed over the last 15 years. Prior to 2004, when patients failed primary ADT, treatments were administered solely for palliation. The landmark trials by Tannock et al.22 and Petrylak et al.23 in 2004 were the first to introduce docetaxel chemotherapy in mCRPC patients that were shown to improve their survival. However, since docetaxel was FDA approved, five additional beneficial agents showing a survival advantage have been FDA-approved based on randomized clinical trials (Table 1). These include enzalutamide, and abiraterone, which specifically affect the androgen axis, sipuleucel-T, which stimulates the immune system;24 cabazitaxel, which is another chemotherapeutic agent;25 and radium-223, a radionuclide therapy.26 Other treatments for mCRPC have shown to improve outcomes but have yet been approved by the FDA and will be discussed in another review. Due to the substantial increase in multiple FDA-approved therapeutic agents in patients with CRPC, clinicians are challenged with a plethora of treatment options and multitude potential sequences of these agents, making clinical decision-making in mCRPC significantly more complex.

Table 1. Agents that have been approved for the treatment of metastatic castrate-resistant prostate cancer in the US

table 1 atents approved for treatment of mCRPC

mCRPC is usually a debilitating disease, and patients will most likely benefit from a management strategy formalized by a multidisciplinary team consisting of urologists, medical oncologists, radiation oncologists, nurses, psychologists, and social workers.28 It is imperative to discuss palliation treatment options when considering additional systemic treatment, including management of pain, constipation, anorexia, nausea, depression, and fatigue.

Another crucial point to consider when establishing the appropriate treatment sequence in this disease space is the associated cost. Using models that included additional lines of treatment before or after docetaxel, the mean cost of mCRPC treatment during a mean period of 28.1 months was approximately $48,000 per patient.29 This cost is quite high due to the fact that patients may receive multiple lines of therapy and incur ongoing medical services during the course of their disease.30

Only two trials have demonstrated a marginal survival benefit for patients remaining on LHRH analogs instead of adding second- and third-line therapies.31, 32 Studies have shown that CRPC is not resistant to ADT, but rather hypersensitive to it.10 Treatment-mediated selection pressure during ADT causes the AR to amplify, and ensure the situation does not escalate, ADT is continued to be administered in the mCRPC setting. Treatment-mediated selection pressure also continues throughout the entire lifespan of the tumor, intensifying the need to correctly sequence therapies. However, because prospective data are lacking, the minute potential benefit of continuing castration still outweighs the minimal risk of this treatment. In addition, all subsequently approved treatments have been studied in men with ongoing ADT, adding another reason why it should be continued.

Before delving into the actual available treatment options, it is important to recognize that it is still unclear when to begin therapy in mCRPC patients who are completely asymptomatic. It is still unknown whether earlier treatment is superior, or if we should wait until the patient becomes symptomatic and develops pain. Before starting treatment, we should consider the patient’s existing comorbidities and expected adverse effects of starting therapy. Patients with early-stage mCRPC in the COU-AA-302 trial who received abiraterone typically survived almost one year longer than those who received placebo (median OS, 53.6 months vs. 41.8 months, respectively, HR, 0.61; 95% CI, 0.43 to 0.87; P = .006).33 Thus, early-stage mCRPC patients benefited from earlier start of abiraterone. In the same trial patients with asymptomatic or mildly symptomatic mCRPC, with baseline PSA < 15.6 ng/mL abiraterone also led to a faster rate and a greater degree of PSA decline than placebo.34 Although the currently available data is limited, it most likely suggests that starting treatment earlier rather than later is more advantageous.33, 34

Approved first-line treatment options for metastatic castrate-resistant prostate cancer

Abiraterone

Abiraterone is an antiandrogen which is an inhibitor of 17α-hydroxylase/C17,20-lyase (CYP17) enzyme. The COU-AA-302 phase III study evaluated abiraterone in 1,088 chemo-naïve, asymptomatic or mildly symptomatic mCRPC patients without visceral metastases. In this trial patients were randomized to abiraterone acetate or placebo, both combined with prednisone35 (Figure 1). Patients were stratified by either the Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 and by asymptomatic or mildly symptomatic disease.35 OS and radiographic progression-free survival (rPFS) was the co-primary end-points. The trial demonstrated that after a median follow-up of 22.2 months, there was a significant improvement of rPFS in the abiraterone arm (median 16.5 vs. 8.2 months, HR 0.52, p < 0.001). At the final analysis after a median follow-up of 49.2 months, the OS end-point was significantly positive (34.7 vs. 30.3 months, HR: 0.81, 95% CI: 0.70-0.93, p = 0.0033).36 It is important to remember that mCRPC spans a broad prognostic spectrum even when it is chemotherapy-naïve.37 In an analysis of the abiraterone arm of the COU-AA-302 study, patients who had no pain at baseline, normal alkaline phosphatase and LDH levels, and less than 10 bone metastases had a median OS of 42.6 months.37 However, patients with more risk factors for progression had significantly shorter median OS.37 When assessing the toxicity profile of abiraterone, it seemed to confer more adverse events related to mineralocorticoid excess and liver function abnormalities, but these were mostly graded 1-2 adverse effects. Lastly, abiraterone was also shown to be equally effective in the elderly population (> 75 years).38

figure 1 COU AA 302 study

Figure 1. COU-AA-302 study design

Enzalutamide

Enzalutamide is a nonsteroidal antiandrogen. The PREVAIL study which is a randomized phase III trial included 1,717 chemo-naïve mCRPC patients and patients with visceral metastases were eligible as well.39 This trial compared enzalutamide to placebo (Figure 2). The PREVAIL trial showed a significant improvement in enzalutamide-treated patients in both co-primary endpoints, which included rPFS (HR: 0.186; CI: 0.15-0.23, p < 0.0001), and OS (HR: 0.706; CI: 0.6-0.84, p < 0.001). Extended follow-up and final analysis confirmed a benefit in OS and rPFS for enzalutamide.40 In 78% of patients treated with enzalutamide a PSA decrease of more than 50% was reported. The most common clinically relevant adverse events were fatigue and hypertension. Enzalutamide was also equally effective and well-tolerated in older men (> 75 years)41 and in those with or without visceral metastases.42 However, for men with liver metastases, there seemed to be no discernible benefit.43 The TERRAIN trial compared enzalutamide with bicalutamide, an older antiandrogen, in a randomized double-blind phase II study, showing a significant improvement in PFS (15.7 months vs. 5.8 months, HR: 0.44, p < 0.0001) in favor of enzalutamide.44

figure 2 PREVAIL study

Figure 2. PREVAIL study design

Docetaxel

The landmark trial TAX 327 showed a significant improvement in median OS of 2-2.9 months in mCRPC patients treated with docetaxel-based chemotherapy when compared to patients who were treated with mitoxantrone plus prednisone therapy.22 The SWOG 9916 trial compared mitoxantrone to docetaxel and showed similar results23 (Figure 3). The standard first-line chemotherapy is docetaxel 75 mg/m2 in three-weekly doses combined with prednisone 5 mg twice a day, up to ten cycles. There are several important prognostic factors to consider when administering docetaxel: visceral metastases, pain, anemia (Hb < 13 g/dL), bone scan progression, and prior estramustine therapy. These prognostic factors may help to stratify response to docetaxel. Using these prognostic factors the disease can be categorized into low, intermediate and high risk, with significantly different corresponding median OS estimates of 25.7, 18.7 and 12.8 months, respectively.45 Although age by itself is not a contraindication to docetaxel therapy, patients must be fit enough to endure this type of treatment and comorbidities should be assessed prior to treatment initiation. In men who are thought to be unable to tolerate the standard dose and schedule of docetaxel, this can be decreased from 75 to 50 mg/m2 every two weeks, showing less grade 3-4 adverse events and a longer time to treatment failure.46

figure 3 SWOG 9916 and TAX trials

Figure 3. SWOG 9916 and TAX 327 trial designs

Sipuleucel-T

Sipuleucel-T, an autologous active cellular immunotherapy, was shown in a phase III trial (IMPACT trial) to confer a survival benefit in 512 asymptomatic or minimally symptomatic mCRPC patients when compared to placebo24 (Figure 4). After a median follow-up of 34 months, the median survival was significantly higher in the sipuleucel-T group (25.8 vs. 21.7 months, with an HR of 0.78,p = 0.03).24 Importantly, no PSA decline was observed during or after treatment and PFS was similar in both arms. The overall tolerance to sipuleucel-T was very good, with mostly grade 1-2 adverse events occurring. Currently, this treatment is only available in the US and is no longer available in Europe.

figure 4 IMPACT trial

Figure 4. IMPACT trial design

Conclusions

In the last 15 years, there has been considerable scientific progress and investment in drug development for patients with mCRPC. This has resulted in the FDA approval of several lines of systemic therapies on grounds of pain palliation, minimizing disease adverse effects, and OS prolongation. To date, the reported impact on OS in mCRPC patients from each of these individual agents is still modest, resulting in an addition of only a few months. It is necessary to enhance our understanding of the disease biology of mCRPC, integrate a comprehensive molecular understanding of castration resistance, and analyze mechanisms of resistance to current therapies to improve future treatment development. It is also crucial to invest and develop predictive biomarkers to assist in the personalization of therapy. Lastly, on a more practical note, more data is needed on the appropriate second and third-line therapies, and sequencing and combination of available medications, discussed in more detail in the next review article (“Beyond first line treatment of metastatic castrate-resistant prostate cancer”).

Published Date: November 19th, 2019
Written by: Hanan Goldberg, MD
References:
  1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA: A Cancer Journal for Clinicians. 2019;69(1):7-34.
  2. Moyer VA. Screening for prostate cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. Jul 17 2012;157(2):120-134.
  3. Fedewa SA, Ward EM, Brawley O, Jemal A. Recent Patterns of Prostate-Specific Antigen Testing for Prostate Cancer Screening in the United States. JAMA Intern Med. Jul 1 2017;177(7):1040-1042.
  4. Negoita S, Feuer EJ, Mariotto A, Cronin KA, Petkov VI, Hussey SK. Annual Report to the Nation on the Status of Cancer, part II: Recent changes in prostate cancer trends and disease characteristics. Jul 1 2018;124(13):2801-2814.
  5. Amling CL, Blute ML, Bergstralh EJ, Seay TM, Slezak J, Zincke H. Long-term hazard of progression after radical prostatectomy for clinically localized prostate cancer: continued risk of biochemical failure after 5 years. J Urol. Jul 2000;164(1):101-105.
  6. Hotte SJ, Saad F. Current management of castrate-resistant prostate cancer. Curr Oncol. Sep 2010;17 Suppl 2:S72-79.
  7. Saad F, Hotte SJ. Guidelines for the management of castrate-resistant prostate cancer. Canadian Urological Association journal = Journal de l'Association des urologues du Canada. 2010;4(6):380-384.
  8. Tangen CM, Hussain MH, Higano CS, et al. Improved overall survival trends of men with newly diagnosed M1 prostate cancer: a SWOG phase III trial experience (S8494, S8894 and S9346). J Urol. Oct 2012;188(4):1164-1169.
  9. Damodaran S, Lang JM, Jarrard DF. Targeting Metastatic Hormone Sensitive Prostate Cancer: Chemohormonal Therapy and New Combinatorial Approaches. J Urol. May 2019;201(5):876-885.
  10. Mohler JL, Titus MA, Bai S, et al. Activation of the androgen receptor by intratumoral bioconversion of androstanediol to dihydrotestosterone in prostate cancer. Cancer Res. Feb 15 2011;71(4):1486-1496.
  11. Sweeney CJ, Chen Y-H, Carducci M, et al. Chemohormonal Therapy in Metastatic Hormone-Sensitive Prostate Cancer. New England Journal of Medicine. 2015;373(8):737-746.
  12. James ND, Sydes MR, Clarke NW, et al. Addition of docetaxel, zoledronic acid, or both to first-line long-term hormone therapy in prostate cancer (STAMPEDE): survival results from an adaptive, multiarm, multistage, platform randomised controlled trial. Lancet. Mar 19 2016;387(10024):1163-1177.
  13. Fizazi K, Tran N, Fein L, et al. Abiraterone acetate plus prednisone in patients with newly diagnosed high-risk metastatic castration-sensitive prostate cancer (LATITUDE): final overall survival analysis of a randomised, double-blind, phase 3 trial. Lancet Oncol. May 2019;20(5):686-700.
  14. James ND, de Bono JS, Spears MR, et al. Abiraterone for Prostate Cancer Not Previously Treated with Hormone Therapy. N Engl J Med. Jul 27 2017;377(4):338-351.
  15. Armstrong AJ, Szmulewitz RZ, Petrylak DP, et al. ARCHES: A Randomized, Phase III Study of Androgen Deprivation Therapy With Enzalutamide or Placebo in Men With Metastatic Hormone-Sensitive Prostate Cancer. J Clin Oncol. Jul 22 2019:Jco1900799.
  16. Davis ID, Martin AJ, Stockler MR, et al. Enzalutamide with Standard First-Line Therapy in Metastatic Prostate Cancer. New England Journal of Medicine. 2019;381(2):121-131.
  17. Clegg NJ, Wongvipat J, Joseph JD, et al. ARN-509: a novel antiandrogen for prostate cancer treatment. Cancer Res. Mar 15 2012;72(6):1494-1503.
  18. Chi KN, Agarwal N, Bjartell A, et al. Apalutamide for Metastatic, Castration-Sensitive Prostate Cancer. N Engl J Med. Jul 4 2019;381(1):13-24.
  19. Smith MR, Saad F, Chowdhury S, et al. Apalutamide Treatment and Metastasis-free Survival in Prostate Cancer. New England Journal of Medicine. 2018;378(15):1408-1418.
  20. Hussain M, Fizazi K, Saad F, et al. Enzalutamide in Men with Nonmetastatic, Castration-Resistant Prostate Cancer. New England Journal of Medicine. 2018;378(26):2465-2474.
  21. Gartrell BA, Saad F. Managing bone metastases and reducing skeletal related events in prostate cancer. Nat Rev Clin Oncol. Jun 2014;11(6):335-345.
  22. Tannock IF, de Wit R, Berry WR, et al. Docetaxel plus Prednisone or Mitoxantrone plus Prednisone for Advanced Prostate Cancer. New England Journal of Medicine. 2004;351(15):1502-1512.
  23. Petrylak DP, Tangen CM, Hussain MH, et al. Docetaxel and estramustine compared with mitoxantrone and prednisone for advanced refractory prostate cancer. N Engl J Med. Oct 7 2004;351(15):1513-1520.
  24. Kantoff PW, Higano CS, Shore ND, et al. Sipuleucel-T immunotherapy for castration-resistant prostate cancer. N Engl J Med. Jul 29 2010;363(5):411-422.
  25. de Bono JS, Oudard S, Ozguroglu M, et al. Prednisone plus cabazitaxel or mitoxantrone for metastatic castration-resistant prostate cancer progressing after docetaxel treatment: a randomised open-label trial. Lancet. Oct 2 2010;376(9747):1147-1154.
  26. Parker C, Nilsson S, Heinrich D, et al. Alpha Emitter Radium-223 and Survival in Metastatic Prostate Cancer. New England Journal of Medicine. 2013;369(3):213-223.
  27. Crawford ED, Petrylak DP, Shore N, et al. The Role of Therapeutic Layering in Optimizing Treatment for Patients With Castration-resistant Prostate Cancer (Prostate Cancer Radiographic Assessments for Detection of Advanced Recurrence II). Urology. Jun 2017;104:150-159.
  28. Esper PS, Pienta KJ. Supportive care in the patient with hormone refractory prostate cancer. Semin Urol Oncol. Feb 1997;15(1):56-64.
  29. Dragomir A, Dinea D, Vanhuyse M, Cury FL, Aprikian AG. Drug costs in the management of metastatic castration-resistant prostate cancer in Canada. BMC Health Serv Res. Jun 13 2014;14:252.
  30. Wen L, Valderrama A, Costantino ME, Simmons S. Real-World Treatment Patterns in Patients with Castrate-Resistant Prostate Cancer and Bone Metastases. Am Health Drug Benefits. May 2019;12(3):142-149.
  31. Hussain M, Wolf M, Marshall E, Crawford ED, Eisenberger M. Effects of continued androgen-deprivation therapy and other prognostic factors on response and survival in phase II chemotherapy trials for hormone-refractory prostate cancer: a Southwest Oncology Group report. J Clin Oncol. Sep 1994;12(9):1868-1875.
  32. Taylor CD, Elson P, Trump DL. Importance of continued testicular suppression in hormone-refractory prostate cancer. J Clin Oncol. Nov 1993;11(11):2167-2172.
  33. Miller K, Carles J, Gschwend JE, Van Poppel H, Diels J, Brookman-May SD. The Phase 3 COU-AA-302 Study of Abiraterone Acetate Plus Prednisone in Men with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer: Stratified Analysis Based on Pain, Prostate-specific Antigen, and Gleason Score. Eur Urol. Jul 2018;74(1):17-23.
  34. Ryan CJ, Londhe A, Molina A, et al. Relationship of baseline PSA and degree of PSA decline to radiographic progression-free survival (rPFS) in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC): Results from COU-AA-302. Journal of Clinical Oncology. 2013;31(15_suppl):5010-5010.
  35. Ryan CJ, Smith MR, de Bono JS, et al. Abiraterone in metastatic prostate cancer without previous chemotherapy. N Engl J Med. Jan 10 2013;368(2):138-148.
  36. Ryan CJ, Smith MR, Fizazi K, et al. Abiraterone acetate plus prednisone versus placebo plus prednisone in chemotherapy-naive men with metastatic castration-resistant prostate cancer (COU-AA-302): final overall survival analysis of a randomised, double-blind, placebo-controlled phase 3 study. Lancet Oncol. Feb 2015;16(2):152-160.
  37. Ryan CJ, Kheoh T, Li J, et al. Prognostic Index Model for Progression-Free Survival in Chemotherapy-Naive Metastatic Castration-Resistant Prostate Cancer Treated With Abiraterone Acetate Plus Prednisone. Clin Genitourin Cancer. Jul 25 2017.
  38. Roviello G, Cappelletti MR, Zanotti L, et al. Targeting the androgenic pathway in elderly patients with castration-resistant prostate cancer: A meta-analysis of randomized trials. Medicine (Baltimore). Oct 2016;95(43):e4636.
  39. Beer TM, Armstrong AJ, Rathkopf DE, et al. Enzalutamide in metastatic prostate cancer before chemotherapy. N Engl J Med. Jul 31 2014;371(5):424-433.
  40. Beer TM, Armstrong AJ, Rathkopf D, et al. Enzalutamide in Men with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer: Extended Analysis of the Phase 3 PREVAIL Study. Eur Urol. Feb 2017;71(2):151-154.
  41. Graff JN, Baciarello G, Armstrong AJ, et al. Efficacy and safety of enzalutamide in patients 75 years or older with chemotherapy-naive metastatic castration-resistant prostate cancer: results from PREVAIL. Ann Oncol. Feb 2016;27(2):286-294.
  42. Evans CP, Higano CS, Keane T, et al. The PREVAIL Study: Primary Outcomes by Site and Extent of Baseline Disease for Enzalutamide-treated Men with Chemotherapy-naive Metastatic Castration-resistant Prostate Cancer. Eur Urol. Oct 2016;70(4):675-683.
  43. Alumkal JJ, Chowdhury S, Loriot Y, et al. Effect of Visceral Disease Site on Outcomes in Patients With Metastatic Castration-resistant Prostate Cancer Treated With Enzalutamide in the PREVAIL Trial. Clin Genitourin Cancer. Oct 2017;15(5):610-617.e613.
  44. Shore ND, Chowdhury S, Villers A, et al. Efficacy and safety of enzalutamide versus bicalutamide for patients with metastatic prostate cancer (TERRAIN): a randomised, double-blind, phase 2 study. Lancet Oncol. Feb 2016;17(2):153-163.
  45. Armstrong AJ, Garrett-Mayer E, de Wit R, Tannock I, Eisenberger M. Prediction of survival following first-line chemotherapy in men with castration-resistant metastatic prostate cancer. Clin Cancer Res. Jan 1 2010;16(1):203-211.
  46. Kellokumpu-Lehtinen PL, Harmenberg U, Joensuu T, et al. 2-Weekly versus 3-weekly docetaxel to treat castration-resistant advanced prostate cancer: a randomised, phase 3 trial. Lancet Oncol. Feb 2013;14(2):117-124.

The Genetics of Prostate Cancer

Germline mutations in prostate cancer carcinogenesis

Some of the first data to delineate the value of assessment of inherited genetic changes in prostate cancer came from Pritchard and colleagues who assessed the prevalence of mutations in 20 DNA-repair genes among 692 patients with metastatic prostate cancer8. They identified such mutations in 82 men (11.8%).

Written by: Zachary Klaassen, MD, MSc
References: 1. Kang ZJ, Liu YF, Xu LZ, et al. The Philadelphia chromosome in leukemogenesis. Chin J Cancer 2016; 35:48.
2. An X, Tiwari AK, Sun Y, et al. BCR-ABL tyrosine kinase inhibitors in the treatment of Philadelphia chromosome positive chronic myeloid leukemia: a review. Leuk Res 2010; 34(10):1255-68.
3. Lichtenstein P, Holm NV, Verkasalo PK, et al. Environmental and heritable factors in the causation of cancer--analyses of cohorts of twins from Sweden, Denmark, and Finland. N Engl J Med 2000; 343(2):78-85.
4. Stanford JL, Ostrander EA. Familial prostate cancer. Epidemiol Rev 2001; 23(1):19-23.
5. Carter BS, Bova GS, Beaty TH, et al. Hereditary prostate cancer: epidemiologic and clinical features. J Urol 1993; 150(3):797-802.
6. Bostwick DG, Burke HB, Djakiew D, et al. Human prostate cancer risk factors. Cancer 2004; 101(10 Suppl):2371-490.
7. Alvarez-Cubero MJ, Saiz M, Martinez-Gonzalez LJ, et al. Genetic analysis of the principal genes related to prostate cancer: a review. Urol Oncol 2013; 31(8):1419-29.
8. Pritchard CC, Mateo J, Walsh MF, et al. Inherited DNA-Repair Gene Mutations in Men with Metastatic Prostate Cancer. N Engl J Med 2016; 375(5):443-53.
9. Castro E, Romero-Laorden N, Del Pozo A, et al. PROREPAIR-B: A Prospective Cohort Study of the Impact of Germline DNA Repair Mutations on the Outcomes of Patients With Metastatic Castration-Resistant Prostate Cancer. J Clin Oncol 2019; 37(6):490-503.
10. Nicolosi P, Ledet E, Yang S, et al. Prevalence of Germline Variants in Prostate Cancer and Implications for Current Genetic Testing Guidelines. JAMA Oncol 2019; 5(4):523-528.
11. Mateo J, Carreira S, Sandhu S, et al. DNA-Repair Defects and Olaparib in Metastatic Prostate Cancer. N Engl J Med 2015; 373(18):1697-708.
12. Robinson D, Van Allen EM, Wu YM, et al. Integrative clinical genomics of advanced prostate cancer. Cell 2015; 161(5):1215-1228.
13. Giri VN, Knudsen KE, Kelly WK, et al. Role of Genetic Testing for Inherited Prostate Cancer Risk: Philadelphia Prostate Cancer Consensus Conference 2017. J Clin Oncol 2018; 36(4):414-424.
14. Wallis CJ, Nam RK. Prostate Cancer Genetics: A Review. EJIFCC 2015; 26(2):79-91.
15. Ahmad AS, Vasiljevic N, Carter P, et al. A novel DNA methylation score accurately predicts death from prostate cancer in men with low to intermediate clinical risk factors. Oncotarget 2016; 7(44):71833-71840.
16. Majumdar S, Buckles E, Estrada J, et al. Aberrant DNA methylation and prostate cancer. Curr Genomics 2011; 12(7):486-505.

The Current Status of Immunotherapy for Prostate Cancer

The Prostate Cancer Immune Microenvironment

The microenvironment associated with prostate cancer includes low cytolytic activity of natural killer (NK) cells,5 high secretion of TGF-beta by prostate tissue (which inhibits NK and lymphocyte function),6 and recruitment of T regulatory cells that down-regulate antitumor immunity.7 As such, the prostate cancer microenvironment has been described as an immunosuppressive state. Furthermore, based on the chronicity of the prostate cancer disease spectrum, the immune microenvironment is likely dynamic, with changes over time/clinical states and with treatment exposure.8 For example, there are increased tumor-infiltrating lymphocytes in the prostate bed following androgen deprivation therapy,9 and higher levels of PD-1 ligand and PD-L2 expression on the surface of enzalutamide-treated prostate cancer cells.10 Several aspects make prostate cancer attractive for immunotherapy-based treatment options, including a high-level of tumor-associated antigens such as prostate-specific antigen (PSA), prostate acid phosphatase (PAP), and prostate-specific membrane antigen (PSMA).

Cell-based vaccines

Cell-based vaccines consist of whole cells that are modified in order to induce anti-tumor immune responses. Sipuleucel-T is an autologous vaccine processed following peripheral dendritic cell collection via leukapheresis. This is then incubated with GCS-F and PAP protein, followed by reinfusion into the patient (after a 36-44 hour period) in order to generate a PAP-specific CD4+ and CD8+ T cell response.11,12

Sipuleucel-T was FDA approved based on results of the Phase III IMPACT clinical trial.1 This trial enrolled 512 patients with mCRPC who had asymptomatic disease/minimally symptomatic with no visceral metastases, randomizing men to three infusions of sipuleucel-T (n=341) or placebo (n=171). The IMPACT trial noted a 4.1-month improvement in overall survival (OS) for those taking sipuleucel-T compared to placebo and a 22% reduction in risk of death. There was no difference between the groups with regards to objective disease progression or PSA response (secondary endpoints). An assessment of safety profile for patients in this study found that the treatment was overall well tolerated with minimal concern for severe adverse events.13 Furthermore, immunologic assessment showed that patients with high antibody titers against PA2024 benefited the most from treatment, noting longer survival.1 Despite the results and safety profile of IMPACT, reported nearly a decade ago, the use of sipuleucel-T has not been widely adopted primarily due to the lack of cost-effectiveness and the infrastructure required to administer this treatment.

Vector-based vaccines

Vector-based vaccines consist of genetically engineered nucleic acids that encode specific tumor-associated antigens transmitted by vectors such as bacterial plasmids or viruses. DNA-based vaccines can be incorporated by host cells and generate an immune response to recruiting antigen-presenting cells. pTVG-HP is a DNA plasmid vector vaccine that encodes PAP protein. pTVG-HP has been tested in the non-metastatic CRPC setting, demonstrating increased PSA doubling time from 6.5 months to 9.3 months after one year of treatment.14

PROSTVAC is a PSA-target pox-virus-based vaccine. PROSTVAC was tested in a Phase II study of 125 patients with minimally symptomatic mCRPC who were randomized to receive the vaccine or placebo.15 Although the study was negative for its primary endpoint of progression-free survival (PFS), OS after 3 years of follow-up was significantly increased by 8.5 months (25.1 vs 16.6 months; HR 0.56; p=0.0061).

PROSTVAC was subsequently tested in a Phase III trial that reported results earlier this year.16 Patients were randomly assigned to PROSTVAC (n = 432), PROSTVAC plus granulocyte-macrophage colony-stimulating (GMCS) factor (n = 432), or placebo (n = 433), stratified by PSA (< 50 ng/mL vs. >= 50 ng/mL) and lactate dehydrogenase (< 200 vs >= 200 U/L). The primary endpoint for this trial was OS, and secondary endpoints were patients alive without events (AWE): radiographic progression, pain progression, chemotherapy initiation, or death at 6 months. Unfortunately, neither active treatment had an effect on median OS: (i) PROSTVAC: 34.4 months, hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.84-1.20 (ii) PROSTVAC plus GMCS factor: 33.2 months, HR 1.02, 95% CI 0.86-1.22 (iii) placebo: 34.3 months. Furthermore, AWE at 6 months was similar between the arms. Based on these results, the authors noted that focus is currently ongoing for combination therapies.

DCVAC/PCa is an autologous dendritic cell vaccine derived from mononuclear cells that are pulsed with killed prostate cancer cells. In a Phase I/II trial, there were 25 men with mCRPC that received DCVAC/PCa plus docetaxel, demonstrating good tolerability and a median OS of 19 months.17 Currently, there is a Phase III (VIABLE) trial of DCVAC/PCa ongoing, which began accrual in 2014, with a target of 1,170 patients and planned completion date in 2020.

Immune Checkpoint inhibitors

Checkpoint inhibitors are antibodies that target molecules, such as cytotoxic T-lymphocyte protein 4 (CTLA-4) or PD-1 and its ligand PD-L1. Among men with mCRPC, ipilimumab was tested in the Phase III for those who had progressed on docetaxel chemotherapy, randomizing 799 patients to ipilimumab or placebo after bone-directed radiotherapy.18 The primary endpoint was OS, with no difference between the groups (ipilimumab 11.2 months vs placebo 10 months; HR 0.85, p=0.053); however, there was a small benefit in PFS favoring ipilimumab (4.0 vs 3.1 months; HR 0.70, p < 0.0001). More recently, Beer et al.19 reported findings of another Phase III trial randomizing 602 patients (2:1) with metastatic chemotherapy-naïve CRPC to ipilimumab vs placebo. Similar to the post-docetaxel patients, there was no difference in OS between the groups (HR 1.11, 95% CI 0.88-1.39), however men receiving ipilimumab had improved PFS (5.6 months vs 3.8; HR 0.67, 95% CI 0.55-0.81) compared to those receiving placebo.

Pembrolizumab has recently moved into the mCRPC arena, receiving FDA approval in a tumor agnostic indication for MSI-high (MSI-H) mutation CRPC patients in 2017. A study from the Memorial Sloan Kettering Cancer Center assessed the prevalence of MSI-H/dMMR prostate cancer among 1,033 patients treated at their institution,20 finding that 32 (3.1%) had MSI-H/dMMR disease. This included 23 patients (2.2%) that had tumors with high MSIsensor scores, and 7 of the 32 MSI-H/dMMR patients (21.9%) with pathogenic germline mutation in a Lynch syndrome-associated gene. Eleven patients with MSI-H/dMMR CRPC received anti-PD-1/PD-L1 therapy and six of these had a greater than 50% decline in PSA levels. Based on these data, experts in the field of advanced prostate cancer feel that every mCRPC patient should be tested for MSI-H status and potential pembrolizumab eligibility.

The KEYNOTE-028 study was a trial of pembrolizumab in advanced solid tumors among patients with PD-1 expression ≥1% of tumor or stromal cells. Among 245 men screened, there were 35 PD-1% (14.3%) and 23 patients who enrolled.21 There were four partial responses, for an objective response rate of 17.4% and 8 of 23 (34.8%) patients had stable disease. Median duration of response was 13.5  months, and median PFS and OS were 3.5 and 7.9 months, respectively. Furthermore, the 6-month PFS and OS rates were 34.8% and 73.4%, respectively. Recently, off-label use of pembrolizumab among a heavily pre-treated population of mCRPC patients has recently been reported. At the 2019 ASCO GU meeting, Tucker and colleagues presented data on 51 patients, 86% of which had received three or more prior lines of therapy. Most patients had previously received abiraterone (88%), docetaxel (86%), enzalutamide (80%), and sipuleucel-T (74%). Among these patients, 16% had a >50% confirmed PSA decline with pembrolizumab, with 8% having >90% PSA decline. Fifty-nine percent of men were treated with some form of concurrent therapy along with pembrolizumab, most commonly enzalutamide (47%).

At the 2019 ASCO GU meeting, results of the Phase II KEYNOTE-650 were also presented. This trial tested the combination of nivolumab plus ipilimumab for men with mCRPC. There were two cohorts for this study: cohort 1 – asymptomatic or minimally symptomatic, who had progressed after at least 1 second generation hormone therapy with no prior chemotherapy, and cohort 2 – progression after chemotherapy. Overall response rates were 26% in cohort 1 and 10% in cohort 2, including two patients in each cohort who had a complete response. Median time to response was approximately two months. PSA response rate was 18% in cohort 1 and 10% in cohort 2.

Future Directions

Unlike many other tumor sites, to date, there has not been robust data to demonstrate a large role for immunotherapy in patients with mCRPC. However, there are several potential ways to increase immunotherapy response with the goal of improving the outcomes of immunotherapy for prostate cancer: (i) combination therapy, (ii) immune modulation, (iii) biomarkers for improving patient selection.

Options for combination therapies:

1) Combination of immunotherapies: multiple vaccines, vaccine plus an immune checkpoint inhibitor, or an immunocytokine plus an immune checkpoint inhibitor. KEYNOTE-650 combining nivolumab plus ipilimumab is an example of improved efficacy among patients receiving combination therapy.

2) Combinations with therapies to capitalize on immunologic synergy: these studies assess the effect of the addition of other accepted treatments such enzalutamide, poly ADP ribose polymerase PARP inhibitors, radium-223, and docetaxel to immunotherapy regimens.

3) Given the changing microenvironment of prostate cancer across disease states, beginning combination immunotherapy earlier (castration-sensitive) may improve the immunotherapeutic benefit.

There are several options of immunomodulatory agents that target the tumor microenvironment to improve immunotherapy efficacy. Docetaxel has been proven to induce immunogenic modulations, such as increasing expression of ICAM-1, MUC-1, and MHC class 1 molecules.22 Additionally, tasquinimod is an immunomodulatory agent that blocks S100A9, a key regulatory molecule of myeloid cells. In a Phase II trial of 206 asymptomatic chemotherapy-naïve mCRPC patients randomized to tasquinimod vs placebo, men receiving tasquinimod had significantly improved disease progression (7.6 vs 3.3 months, p = 0.0042).23 Unfortunately, a Phase III trial assessing tasquinimod did not improve OS (21.3 for tasquinimod vs 24 months for placebo, HR 1.10, p=0.25), however, there was an improvement in radiographic PFS (7.0 months vs 4.4 months, HR 0.64, p = 0.001).24

Biomarkers continue to be an active area of research, not just for the selection of appropriate patients for immunotherapy, but also for other treatment regimens for advanced prostate cancer (ie. BRCA status for selecting patients for PARP inhibitors).

As follows is a summary of several of the current biomarkers as related to immunotherapy and prostate cancer (adapted from Maia and Hansen8):

current biomarkers as related to immunotherapy and prostate cancer

As follows is a summary of ongoing, recruiting phase III trial assessing immunotherapy in prostate cancer:

ongoing recruiting phase III trial assessing immunotherapy in prostate cancer

Conclusion 

To date, immunotherapy in prostate cancer has been less successful than other cancer types, with only Sipuleucel-T demonstrating an OS advantage of 4.1 months in a Phase III trial. Given the plethora of other treatment options, Sipuleucel-T is uncommonly used. However, with improved combination therapy, immunomodulation and biomarkers in addition to ongoing Phase III trials, there are additional assessments and results in upcoming that may improve the immunotherapy landscape and add to the armamentarium of treatment options for men with advanced prostate cancer.

Published Date: November 2019

Written by: Zachary Klaassen, MD, MSc
References: 1. Kantoff PW, Higano CS, Shore ND, et al. Sipuleucel-T immunotherapy for castration-resistant prostate cancer. N Engl J Med. 2010;363(5):411-422.
2. Ryan CJ, Smith MR, Fizazi K, et al. Abiraterone acetate plus prednisone versus placebo plus prednisone in chemotherapy-naive men with metastatic castration-resistant prostate cancer (COU-AA-302): final overall survival analysis of a randomised, double-blind, placebo-controlled phase 3 study. Lancet Oncol. 2015;16(2):152-160.
3. de Bono JS, Oudard S, Ozguroglu M, et al. Prednisone plus cabazitaxel or mitoxantrone for metastatic castration-resistant prostate cancer progressing after docetaxel treatment: a randomised open-label trial. Lancet. 2010;376(9747):1147-1154.
4. Parker C, Nilsson S, Heinrich D, et al. Alpha emitter radium-223 and survival in metastatic prostate cancer. N Engl J Med. 2013;369(3):213-223.
5. Pasero C, Gravis G, Guerin M, et al. Inherent and Tumor-Driven Immune Tolerance in the Prostate Microenvironment Impairs Natural Killer Cell Antitumor Activity. Cancer Res. 2016;76(8):2153-2165.
6. Flavell RA, Sanjabi S, Wrzesinski SH, Licona-Limon P. The polarization of immune cells in the tumour environment by TGFbeta. Nat Rev Immunol. 2010;10(8):554-567.
7. Sfanos KS, Bruno TC, Maris CH, et al. Phenotypic analysis of prostate-infiltrating lymphocytes reveals TH17 and Treg skewing. Clin Cancer Res. 2008;14(11):3254-3261.
8. Maia MC, Hansen AR. A comprehensive review of immunotherapies in prostate cancer. Crit Rev Oncol Hematol. 2017;113:292-303.
9. Thoma C. Prostate cancer: Towards effective combination of ADT and immunotherapy. Nat Rev Urol. 2016;13(6):300.
10. Bishop JL, Sio A, Angeles A, et al. PD-L1 is highly expressed in Enzalutamide resistant prostate cancer. Oncotarget. 2015;6(1):234-242.
11. Drake CG. Prostate cancer as a model for tumour immunotherapy. Nat Rev Immunol. 2010;10(8):580-593.
12. Ren R, Koti M, Hamilton T, et al. A primer on tumour immunology and prostate cancer immunotherapy. Can Urol Assoc J. 2016;10(1-2):60-65.
13. Hall SJ, Klotz L, Pantuck AJ, et al. Integrated safety data from 4 randomized, double-blind, controlled trials of autologous cellular immunotherapy with sipuleucel-T in patients with prostate cancer. J Urol. 2011;186(3):877-881.
14. McNeel DG, Dunphy EJ, Davies JG, et al. Safety and immunological efficacy of a DNA vaccine encoding prostatic acid phosphatase in patients with stage D0 prostate cancer. J Clin Oncol. 2009;27(25):4047-4054.
15. Kantoff PW, Schuetz TJ, Blumenstein BA, et al. Overall survival analysis of a phase II randomized controlled trial of a Poxviral-based PSA-targeted immunotherapy in metastatic castration-resistant prostate cancer. J Clin Oncol. 2010;28(7):1099-1105.
16. Gulley JL, Borre M, Vogelzang NJ, et al. Phase III Trial of PROSTVAC in Asymptomatic or Minimally Symptomatic Metastatic Castration-Resistant Prostate Cancer. J Clin Oncol. 2019;37(13):1051-1061.
17. Podrazil M, Horvath R, Becht E, et al. Phase I/II clinical trial of dendritic-cell based immunotherapy (DCVAC/PCa) combined with chemotherapy in patients with metastatic, castration-resistant prostate cancer. Oncotarget. 2015;6(20):18192-18205.
18. Kwon ED, Drake CG, Scher HI, et al. Ipilimumab versus placebo after radiotherapy in patients with metastatic castration-resistant prostate cancer that had progressed after docetaxel chemotherapy (CA184-043): a multicentre, randomised, double-blind, phase 3 trial. Lancet Oncol. 2014;15(7):700-712.
19. Beer TM, Kwon ED, Drake CG, et al. Randomized, Double-Blind, Phase III Trial of Ipilimumab Versus Placebo in Asymptomatic or Minimally Symptomatic Patients With Metastatic Chemotherapy-Naive Castration-Resistant Prostate Cancer. J Clin Oncol. 2017;35(1):40-47.
20. Abida W, Cheng ML, Armenia J, et al. Analysis of the Prevalence of Microsatellite Instability in Prostate Cancer and Response to Immune Checkpoint Blockade. JAMA Oncol. 2018.
21. Hansen AR, Massard C, Ott PA, et al. Pembrolizumab for advanced prostate adenocarcinoma: findings of the KEYNOTE-028 study. Ann Oncol. 2018;29(8):1807-1813.
22. Hodge JW, Garnett CT, Farsaci B, et al. Chemotherapy-induced immunogenic modulation of tumor cells enhances killing by cytotoxic T lymphocytes and is distinct from immunogenic cell death. Int J Cancer. 2013;133(3):624-636.
23. Pili R, Haggman M, Stadler WM, et al. Phase II randomized, double-blind, placebo-controlled study of tasquinimod in men with minimally symptomatic metastatic castrate-resistant prostate cancer. J Clin Oncol. 2011;29(30):4022-4028.
24. Sternberg C, Armstrong A, Pili R, et al. Randomized, Double-Blind, Placebo-Controlled Phase III Study of Tasquinimod in Men With Metastatic Castration-Resistant Prostate Cancer. J Clin Oncol. 2016;34(22):2636-2643.

Oligometastatic Prostate Cancer – Treatment of the Primary Tumor and Metastasis Directed Therapy

In 2018 1.3 million prostate cancer (PCa) cases were diagnosed worldwide, with approximately 20% having metastatic disease.1 Oligometastatic PCa is defined as a state of low-volume metastatic disease that appears to be prognostically different and likely amenable to different treatment options, which could potentially change the disease trajectory when compared with high-volume metastatic disease.2 
Written by: Hanan Goldberg, MD
References: 1. Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA: a cancer journal for clinicians 2018; 68(6): 394-424.
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8. Foster CC, Weichselbaum RR, Pitroda SP. Oligometastatic prostate cancer: Reality or figment of imagination? Cancer 2019; 125(3): 340-52.
9. Triggiani L, Alongi F, Buglione M, et al. Efficacy of stereotactic body radiotherapy in oligorecurrent and in oligoprogressive prostate cancer: new evidence from a multicentric study. British journal of cancer 2017; 116(12): 1520-5.
10. Pembroke CA, Fortin B, Kopek N. Comparison of survival and prognostic factors in patients treated with stereotactic body radiotherapy for oligometastases or oligoprogression. Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology 2018; 127(3): 493-500.
11. Jorgensen T, Muller C, Kaalhus O, Danielsen HE, Tveter KJ. Extent of disease based on initial bone scan: important prognostic predictor for patients with metastatic prostatic cancer. Experience from the Scandinavian Prostatic Cancer Group Study No. 2 (SPCG-2). European urology 1995; 28(1): 40-6.
12. Gandaglia G, Karakiewicz PI, Briganti A, et al. Impact of the Site of Metastases on Survival in Patients with Metastatic Prostate Cancer. European urology 2015; 68(2): 325-34.
13. Gakis G, Boorjian SA, Briganti A, et al. The role of radical prostatectomy and lymph node dissection in lymph node-positive prostate cancer: a systematic review of the literature. European urology 2014; 66(2): 191-9.
14. von Bodman C, Godoy G, Chade DC, et al. Predicting biochemical recurrence-free survival for patients with positive pelvic lymph nodes at radical prostatectomy. The Journal of urology 2010; 184(1): 143-8.
15. Briganti A, Karnes JR, Da Pozzo LF, et al. Two positive nodes represent a significant cut-off value for cancer specific survival in patients with node positive prostate cancer. A new proposal based on a two-institution experience on 703 consecutive N+ patients treated with radical prostatectomy, extended pelvic lymph node dissection and adjuvant therapy. European urology 2009; 55(2): 261-70.
16. Francini E, Gray KP, Xie W, et al. Time of metastatic disease presentation and volume of disease are prognostic for metastatic hormone sensitive prostate cancer (mHSPC). 2018; 78(12): 889-95.
17. Linch M, Goh G, Hiley C, et al. Intratumoural evolutionary landscape of high-risk prostate cancer: the PROGENY study of genomic and immune parameters. Annals of oncology : official journal of the European Society for Medical Oncology 2017; 28(10): 2472-80.
18. Gundem G, Van Loo P, Kremeyer B, et al. The evolutionary history of lethal metastatic prostate cancer. Nature 2015; 520(7547): 353-7.
19. Cooper CS, Eeles R, Wedge DC, et al. Analysis of the genetic phylogeny of multifocal prostate cancer identifies multiple independent clonal expansions in neoplastic and morphologically normal prostate tissue. Nature genetics 2015; 47(4): 367-72.
20. Larbi A, Dallaudiere B, Pasoglou V, et al. Whole body MRI (WB-MRI) assessment of metastatic spread in prostate cancer: Therapeutic perspectives on targeted management of oligometastatic disease. The Prostate 2016; 76(11): 1024-33.
21. Graziani T, Ceci F, Castellucci P, et al. (11)C-Choline PET/CT for restaging prostate cancer. Results from 4,426 scans in a single-centre patient series. European journal of nuclear medicine and molecular imaging 2016; 43(11): 1971-9.
22. McAllister SS, Gifford AM, Greiner AL, et al. Systemic endocrine instigation of indolent tumor growth requires osteopontin. Cell 2008; 133(6): 994-1005.
23. Kaplan RN, Riba RD, Zacharoulis S, et al. VEGFR1-positive haematopoietic bone marrow progenitors initiate the pre-metastatic niche. Nature 2005; 438(7069): 820-7.
24. Bayne CE, Williams SB, Cooperberg MR, et al. Treatment of the Primary Tumor in Metastatic Prostate Cancer: Current Concepts and Future Perspectives. European urology 2016; 69(5): 775-87.
25. Locke JA, Dal Pra A, Supiot S, Warde P, Bristow RG. Synergistic action of image-guided radiotherapy and androgen deprivation therapy. Nature reviews Urology 2015; 12(4): 193-204.
26. Kalina JL, Neilson DS, Comber AP, et al. Immune Modulation by Androgen Deprivation and Radiation Therapy: Implications for Prostate Cancer Immunotherapy. Cancers (Basel) 2017; 9(2): 13.
27. Heidenreich A, Pfister D, Porres D. Cytoreductive radical prostatectomy in patients with prostate cancer and low volume skeletal metastases: results of a feasibility and case-control study. The Journal of urology 2015; 193(3): 832-8.
28. Bianchini D, Lorente D, Rescigno P, et al. Effect on Overall Survival of Locoregional Treatment in a Cohort of De Novo Metastatic Prostate Cancer Patients: A Single Institution Retrospective Analysis From the Royal Marsden Hospital. Clinical genitourinary cancer 2017; 15(5): e801-e7.
29. Gratzke C, Engel J, Stief CG. Role of radical prostatectomy in metastatic prostate cancer: data from the Munich Cancer Registry. European urology 2014; 66(3): 602-3.
30. Culp SH, Schellhammer PF, Williams MB. Might men diagnosed with metastatic prostate cancer benefit from definitive treatment of the primary tumor? A SEER-based study. European urology 2014; 65(6): 1058-66.
31. O'Shaughnessy MJ, McBride SM, Vargas HA, et al. A Pilot Study of a Multimodal Treatment Paradigm to Accelerate Drug Evaluations in Early-stage Metastatic Prostate Cancer. Urology 2017; 102: 164-72.
32. Satkunasivam R, Kim AE, Desai M, et al. Radical Prostatectomy or External Beam Radiation Therapy vs No Local Therapy for Survival Benefit in Metastatic Prostate Cancer: A SEER-Medicare Analysis. The Journal of urology 2015; 194(2): 378-85.
33. Loppenberg B, Dalela D, Karabon P, et al. The Impact of Local Treatment on Overall Survival in Patients with Metastatic Prostate Cancer on Diagnosis: A National Cancer Data Base Analysis. European urology 2017; 72(1): 14-9.
34. Boeve LMS, Hulshof M, Vis AN, et al. Effect on Survival of Androgen Deprivation Therapy Alone Compared to Androgen Deprivation Therapy Combined with Concurrent Radiation Therapy to the Prostate in Patients with Primary Bone Metastatic Prostate Cancer in a Prospective Randomised Clinical Trial: Data from the HORRAD Trial. European urology 2019; 75(3): 410-8.
35. Parker CC, James ND, Brawley CD, et al. Radiotherapy to the primary tumour for newly diagnosed, metastatic prostate cancer (STAMPEDE): a randomised controlled phase 3 trial. Lancet (London, England) 2018; 392(10162): 2353-66.
36. Sweeney CJ, Chen Y-H, Carducci M, et al. Chemohormonal Therapy in Metastatic Hormone-Sensitive Prostate Cancer. New England Journal of Medicine 2015; 373(8): 737-46.
37. Burdett S, Boeve LM, Ingleby FC, et al. Prostate Radiotherapy for Metastatic Hormone-sensitive Prostate Cancer: A STOPCAP Systematic Review and Meta-analysis. European urology 2019; 76(1): 115-24.
38. Potters L, Kavanagh B, Galvin JM, et al. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) practice guideline for the performance of stereotactic body radiation therapy. International journal of radiation oncology, biology, physics 2010; 76(2): 326-32.
39. De Bleser E, Tran PT, Ost P. Radiotherapy as metastasis-directed therapy for oligometastatic prostate cancer. Current opinion in urology 2017; 27(6): 587-95.
40. Decaestecker K, De Meerleer G, Lambert B, et al. Repeated stereotactic body radiotherapy for oligometastatic prostate cancer recurrence. Radiat Oncol 2014; 9: 135-.
41. Palma DA, Salama JK, Lo SS, et al. The oligometastatic state - separating truth from wishful thinking. Nature reviews Clinical oncology 2014; 11(9): 549-57.
42. Riva G, Marvaso G, Augugliaro M, et al. Cytoreductive prostate radiotherapy in oligometastatic prostate cancer: a single centre analysis of toxicity and clinical outcome. Ecancermedicalscience 2017; 11: 786.
43. Ost P, Reynders D, Decaestecker K, et al. Surveillance or Metastasis-Directed Therapy for Oligometastatic Prostate Cancer Recurrence: A Prospective, Randomized, Multicenter Phase II Trial. Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2018; 36(5): 446-53.
44. Nguyen PL, Alibhai SM, Basaria S, et al. Adverse effects of androgen deprivation therapy and strategies to mitigate them. European urology 2015; 67(5): 825-36.
45. Duchesne GM, Woo HH, Bassett JK, et al. Timing of androgen-deprivation therapy in patients with prostate cancer with a rising PSA (TROG 03.06 and VCOG PR 01-03 [TOAD]): a randomised, multicentre, non-blinded, phase 3 trial. The Lancet Oncology 2016; 17(6): 727-37.
46. Ost P, Bossi A, Decaestecker K, et al. Metastasis-directed therapy of regional and distant recurrences after curative treatment of prostate cancer: a systematic review of the literature. European urology 2015; 67(5): 852-63.
47. Steuber T, Jilg C, Tennstedt P, et al. Standard of Care Versus Metastases-directed Therapy for PET-detected Nodal Oligorecurrent Prostate Cancer Following Multimodality Treatment: A Multi-institutional Case-control Study. European urology focus 2018.
48. Siva S, Bressel M, Murphy DG, et al. Stereotactic Abative Body Radiotherapy (SABR) for Oligometastatic Prostate Cancer: A Prospective Clinical Trial. European urology 2018; 74(4): 455-62.
49. Ploussard G, Gandaglia G, Borgmann H, et al. Salvage Lymph Node Dissection for Nodal Recurrent Prostate Cancer: A Systematic Review. European urology 2018.
50. Zattoni F, Nehra A, Murphy CR, et al. Mid-term Outcomes Following Salvage Lymph Node Dissection for Prostate Cancer Nodal Recurrence Status Post-radical Prostatectomy. European urology focus 2016; 2(5): 522-31.
51. Fossati N, Suardi N, Gandaglia G, et al. Identifying the Optimal Candidate for Salvage Lymph Node Dissection for Nodal Recurrence of Prostate Cancer: Results from a Large, Multi-institutional Analysis. European urology 2019; 75(1): 176-83.
52. Standard Systemic Therapy With or Without Definitive Treatment in Treating Participants With Metastatic Prostate Cancer. 2019. https://clinicaltrials.gov/ct2/show/NCT03678025. (accessed August 8th 2019).
53. Stereotactic Body Radiation for Prostate Oligometastases (ORIOLE). NCT02680587. 2019. https://clinicaltrials.gov/ct2/show/ (accessed August 8th 2019).
54. Radwan N, Phillips R, Ross A, et al. A phase II randomized trial of Observation versus stereotactic ablative RadiatIon for OLigometastatic prostate CancEr (ORIOLE). BMC cancer 2017; 17(1): 453.
55. Rowe SP, Macura KJ, Mena E, et al. PSMA-Based [(18)F]DCFPyL PET/CT Is Superior to Conventional Imaging for Lesion Detection in Patients with Metastatic Prostate Cancer. Mol Imaging Biol 2016; 18(3): 411-9.
56. Sooriakumaran P. Testing radical prostatectomy in men with prostate cancer and oligometastases to the bone: a randomized controlled feasibility trial. BJU international 2017; 120(5b): E8-e20.

Recurrent Urinary Tract Infection (rUTI) in Women Clinical Care Pathway

EVALUATION


Recurrent Urinary Tract Infections (rUTI) is defined as: >2 culture-positive UTIs in 6 months or >3 in one year

1. Take A History - Document symptoms and signs that characterize rUTI episodes and exclude other disorders that could cause the patient’s symptoms (e.g. bacterial vaginosis, vaginal yeast infection, STIs). Ask about the relationship of UTIs to sexual activity, prolonged bladder holding, and bowel irregularity. Rule out noninfectious pelvic and urinary tract sources of symptoms (e.g. overactive bladder, radiation cystitis, bladder pain syndrome, vulvodynia, pelvic organ prolapse, urinary retention/poor bladder emptying, and neurogenic bladder).

Genito-urinary history:  Evaluate for complicating factors including pediatric/congenital urologic conditions (e.g., vesicoureteral reflux, megaureter), nephrolithiasis, flank pain, incomplete bladder emptying, prior bladder/pelvic surgery (especially use of mesh material), vaginal pain, cysts or lesions in the vagina, antiestrogen use, pelvic malignancy, absorbent pad use, fecal incontinence, immunosuppression, and neurologic disease.

Review prior urine culture results to confirm rUTI diagnosis with two or more positive cultures in 6 months or 3 or more in one year.  

2. Perform Physical Exam to include a pelvic examination - Assess for hygiene and fecal contamination, look for urethral diverticulum, vaginal discharge and/or yeast, vaginal cysts, atrophic vaginitis, and pelvic organ prolapse. If prior mesh or pelvic surgery, consider cystoscopy if a vaginal cyst or periurethral fluctuance (pseudo-urethral abscess formation) order pelvic MRI with coil.

3. Collect Urine Specimen for Testing - Send urine specimen for urinalysis (UA) if symptoms suggestive of UTI.  If positive, send the specimen for urine culture and sensitivities.  If microscopic hematuria in the absence of infection work-up alongside initial therapy. If sterile pyuria, rule out STIs and urinary TB (AFB’s). If asymptomatic bacteriuria, do not treat.  Assess for bacterial persistence, if present considers cross-sectional imaging (retroperitoneal ultrasound) and +/- cystoscopy.

4. Perform ultrasound (bladder scan) US PVR (immediately after voiding) - if >150 cc (on 2 separate occasions) and monitor. Consider intermittent self-catheterization if no other source for infection identified and 1st line suppression fails.

TREATMENT

1st Line Therapy (Behavioral/Lifestyle Modifications) and UTI Prevention Measures

  • Diabetic patients: Control blood glucose and avoid glucosuria
  • Fluid intake: Maintain adequate hydration (Hooten recommended drinking 1.5 L of water daily along with the suggestion to start a 500 mL bottle of water at the beginning of every meal and fully drink it before the next meal).
  • Dietary Changes: Cranberry use in all its forms is not supported by current evidence; however, little harm is associated with its use.
  • Probiotic: Use of either oral or intravaginal probiotics to restore the natural vaginal microbiota (Lactobacillus spp. colonies) seems to be a promising approach to reducing antibiotic consumption and to decreasing antimicrobial resistance.  Lactobacilli may especially be useful for women with histories of recurrent, complicated UTIs or on prolonged antibiotic use.   Dietary sources of probiotics may be helpful, these include probiotic yogurt (such as Activia), Greek yogurt, kefir and kombucha juice.
  • Voiding habits: Avoid prolonged holding of urine, avoid delaying urination (peeing)
  • Hygiene: Avoid disruption of normal vaginal flora with spermicides and/ or harsh cleansers. Avoid soaking in tubs, hot tubs and in baths. 
  • Sex: Void before and after intercourse and avoid sequential anal and vaginal intercourse
  • Bowel Regimen – If diarrhea and/or fecal incontinence are present start loperamide. If mild-moderate constipation is present begin bowel regimen including increasing dietary fiber, stool softener, and/or Miralax.  If moderate-severe constipation is present begin bowel regimen (as above) if not on one and consider referral to Primary Care/GI if refractory.
  • Persisting irritative bladder symptoms:  Many women experience irritative bladder symptoms of pressure or discomfort, bladder urgency, burning when peeing after adequate antibiotic treatment.  These symptoms can mimic UTI symptoms and many women are erroneously prescribed another antibiotic but do not exhibit a relief of these irritative symptoms.  Consider one of the following treatment regimens:
      • Prescribe Urelle 81 mg tab, 4 times a day (evenly spaced).  Take each dose with a full glass of water (8 ounces/240 mL). Can take with food if GI upset occurs.
    • Over-the-counter medications:
            • Azo-Pyridium (phenazopyridine) 100 mg or Uricalm MAX 99.5 mg (phenazopyridine). These are not prescription medications but can be found at most pharmacies or drug stores.
            • NSAID (Motrin, Aleve) as the symptoms of UTIs are mostly connected to the inflammatory reaction of the urinary tract due to a significant increase in urinary prostaglandin production, because the onset and duration of clinical symptoms of UTI seem to be strongly connected to prostaglandin levels. Since NSAIDs can inhibit the biosynthesis of prostaglandins, they can be useful in alleviating the symptoms of UTI.
Persistence Acute treatment for breakthrough UTI should start with obtaining a urine culture.  If initiation of empiric antibiotics is requested use prior culture data to choose among first line treatments while culture is pending. Consider antibiotic resistance patterns in each patient as well as in the local community and consider patient allergies, side effects and cost.  Clinical practice guidelines recommend utilization of short duration nitrofurantoin (100 mg BID x 5 days), trimethoprim-sulfamethoxazole (100mg/800mg BID x 3 days), or fosfomycin (1 packet x 1 dose).  

bladder_health_coe.png
 

Follow up in 6 months with the maintenance of records of all symptomatic episodes, antibiotic use, UA, and urine culture results. If 2 or more infections in 6 months move to 2nd line therapy.

2nd Line Therapy (Medications)

Review and Reinforce 1st line Therapy +

  • In Postmenopausal Women with rUTIs:
    • Initiate transvaginal (topical) estrogen and lactobacillus containing probiotics daily.  Vaginal estrogen can be prescribed as Estrace cream 1 gram or Premarin cream 0.5 grams, Vagifem (Yuvafem) 10 mcg tablets (all can be used daily for 2 weeks then twice weekly), Estring, or compounded estrogen for approximately $50 a tube.
      • Estrace cream comes with 1 applicator that always has to be cleaned. Go on the manufacturer's website (www.estracecream.com), click “Request Applicators” and get 24 individually wrapped applicators at no cost, every 3 months.
    • If already on these measures or they are contraindicated or ineffective after 6 months, add methenamine hippurate (Hiprex) 1 gram twice daily plus vitamin C 500 mg twice daily.  
      • Avoid Vitamin C if history of kidney stones
      • If renal insufficiency/decreased GFR, dose methenamine hippurate accordingly
    • In severe cases, consider combined initial therapy with vaginal estrogen, probiotics, methenamine hippurate and vitamin C.
      • An alternative to methenamine hippurate is d-Mannose 500- 750 mg twice/day, a monosaccharide that can be rapidly absorbed and excreted by the urinary tract and can prevent the adhesion of type 1 bacterial fimbriae (bacterial virulence factor, usually caused by E. coli) promoting UTI to the uroepithelium

 

  • In Premenopausal Women with rUTIs
    • With Post-Coital rUTIs:
      • Initiate a single low dose prophylactic antibiotic* within 2 hours of sexual activity for 6-12 months duration OR
      • Has already tried post-coital antibiotics, or has intercourse more than twice per week initiate methenamine hippurate 1 gram twice daily, vitamin C 500 mg twice daily and lactobacillus containing probiotics daily or alternative to methenamine hippurate is d-Mannose 500- 750 mg twice/day.
    • With rUTI unrelated to sexual activity:
      • Consider daily low dose prophylactic antibiotic* for 6-12 months’ duration OR
      • Have already tried daily antibiotics, initiate methenamine hippurate 1 gram twice daily, vitamin C 500 mg twice daily and lactobacillus containing probiotics daily or alternative to methenamine hippurate is d-Mannose 500- 750 mg twice/day
*Prophylactic antibiotic choice should take into account a patient’s prior organism identification and susceptibility profile, drug allergies, and antibiotic stewardship. Nitrofurantoin 50 mg, trimethoprim-sulfamethoxazole 40/200 mg, trimethoprim 100 mg are preferred over fluoroquinolones and/or cephalosporins.

Follow up in 6 months with the maintenance of records of all symptomatic episodes, antibiotic use, UA, and urine culture results. If refractory; consider an evaluation with cross sectional imaging +/- cystoscopy. In refractory patients, alternative prophylactic antibiotics can be tried. In severe refractory cases in patients on intermittent catheterization, intravesical gentamycin can be considered.

figure-1-recurrent-UTI-pathway2x_1.jpg
Published Date: September 26th, 2019
Written by: Diane K. Newman, DNP, ANP-BC, FAAN
References: 1. American Urological Association, the Canadian Urological Association and the Society of Urodynamics Female Pelvic Medicine and Urogenital Reconstruction.   Recurrent uncomplicated UTIs in women. 
2. Hooton TM, Vecchio M, Iroz A, Tack I, Dornic Q, Seksek I, Lotan Y. Effect of increased daily water intake in premenopausal women with recurrent urinary tract infections: A randomized clinical trial. JAMA Intern Med. 2018 Nov 1;178(11):1509-1515. doi: 10.1001/jamainternmed.2018.4204
3. Nicolle et al., Practice Guideline for the Management of Asymptomatic Bacteriuria: 2019 Update by the Infectious Diseases Society of America. Clin Infect Dis. 2019 Mar 21. pii: ciy1121. doi: 10.1093/cid/ciy1121). 
4. Smith AL, Brown J, Wyman JF, Berry A, Newman DK, Stapleton AE. Treatment and prevention of recurrent lower urinary tract infections in women: A rapid review with practice recommendations. J Urol. 2018 Dec;200(6):1174-1191. doi: 10.1016/j.juro.2018.04.088). 
5. Wawrysiuk S, Naber K, Rechberger T, Miotla P. Prevention and treatment of uncomplicated lower urinary tract infections in the era of increasing antimicrobial resistance-non-antibiotic approaches: a systemic review. Arch Gynecol Obstet. 2019 Jul 26. doi: 10.1007/s00404-019-05256-

Prostate Cancer Survivorship

Physical Side Effects


Urinary Dysfunction

Urinary dysfunction is a side effect of both surgical and radiotherapy (RT) for local treatment of prostate cancer (PCa). Surgical side effects typically include a period of urinary incontinence for several months postoperatively followed by a degree of stress urinary incontinence that may persist for months or even years. RT-induced urinary dysfunction typically manifests as bladder irritability/overactivity either during treatment or shortly thereafter. Longer-term urinary dysfunction issues after RT may include urethral strictures necessitating periodic interventions and/or catheterization.

The ProtecT trial randomized 1,643 men from 1999 to 2009 to undergoing either active monitoring (n=545), surgery (n=553), or RT (n=545), finding that at a median 10 years of follow-up, PCa-specific mortality was low irrespective of treatment.2 As part of this trial, patient-reported outcomes were collected and have now become one of the benchmarks for counseling patients with regards to long-term side effects of treatment for localized PCa treatment.3 Questionnaires were completed at the time of diagnosis, at 6 and 12 months after randomization, and annually thereafter. Patients completed validated measures that assessed urinary, bowel, and sexual function and specific effects on quality of life, anxiety, and depression, and general health. The rate of questionnaire completion during follow-up was outstanding at >85% for most measures. Regarding urinary dysfunction, radical prostatectomy (RP) had the greatest negative effect on urinary continence, and although there was some recovery over time, these patients remained worse throughout follow-up compared to patients undergoing active monitoring or RT. Interestingly, RT had little effect on urinary incontinence, and there was a gradual decrease in urinary function over time for the men undergoing active monitoring. Urinary voiding and nocturia were worse in the radiotherapy group at 6 months but then mostly recovered and were similar to the other groups after 12 months. Urinary incontinence has been cited as being the most important factor for decision regret among receiving local therapy for PCa and may be incompletely explained/discussed with ~80% of patients prior to undergoing treatment.4

Sexual Dysfunction

Similar to urinary dysfunction, sexual dysfunction is a common side effect of localized therapy for PCa. Patients undergoing RP will suffer a degree of sexual dysfunction in the immediate postoperative period with a degree of recovering over 12-24 months after surgery. Many studies have been published assessing predictors of postoperative recovery of sexual function, commonly highlighting younger age and adequate function pre-operatively as predictors of post-operative recovery. Men undergoing RT, similar to urinary dysfunction, will not notice an immediate effect on sexual function during the treatment phase, but generally, suffer sexual dysfunction in the years post-radiation.

In the ProtecT trial, RP incurred the greatest degree of sexual dysfunction among all three treatment arms, with some recovery of function over time.3 The negative effect of RT on sexual function was greatest at 6 months, but sexual function then recovered somewhat and was stable thereafter. Sexual dysfunction also declined in the active monitoring group over time.

Primarily secondary to the sexual side effects of localized treatment for PCa, many cancer centers now have fellowship-trained experts that see these patients concomitantly with the oncologist. There are a variety of treatment options offered, including oral PDE-5 inhibitors (sildenafil, tadalafil, etc.), intracavernosal injection therapy, and penile prosthetics.

Bowel Dysfunction

Bowel dysfunction is typically low for patients undergoing RP or active surveillance (AS) but may be a detrimental side effect among men undergoing RT. In the ProtecT trial, bowel function was worse in the RT group at 6 months than in the other groups but then recovered somewhat, except for the increasing frequency of bloody stools; bowel function was unchanged in the active monitoring and RP groups.3

Bowel dysfunction and rectal toxicity has improved with the recent FDA approval of hydrogel rectal spacers. Prior to RT, patients may have a hydrogel rectal spacer (SpaceOAR®) placed in a transperineal fashion in the fat between the rectum and Denonvilliers' fascia. In the pivotal clinical trial assessing hydrogel spacers, 114 patients were enrolled between 2010 and 2011 with 54 patients selected for a hydrogel injection before the beginning of RT.5 Patients were surveyed at various time-points with the EPIC PCa questionnaire – among patients treated with a hydrogel spacer, mean bowel function and bother score changes of >5 points in comparison with baseline levels were found only at the end of RT (10-15 points; p < 0.01). Mean bowel bother score changes of 21 points at the end of RT, 8 points at 2 months, 7 points at 17 months, and 6 points at 63 months after RT were found for patients treated without a spacer. These bowel quality of life results have given hydrogel spacers an option among patients considering RT.

Other health-related effects

There is evidence that both RT and androgen deprivation therapy (ADT) may contribute to the development of coronary heart disease, sudden cardiac death, myocardial infarction, and skeletal-related events such as fracture.6

Psychological Side Effects

Depression and Anxiety

Depression is the most common psychiatric comorbidity among cancer patients, including patients with PCa. Ravi et al.7 previously utilized the SEER-Medicare database to assess the burden of mental health issues (anxiety, major depressive disorder, suicide) in patients with localized PCa. Among 50,586 men >65 years of age without a diagnosis of mental illness, 20.4% of men developed a mental illness with a median 55-month follow-up. Interestingly, patients undergoing WW (29.7%) and RT (29.0%) had a significantly increased incidence of mental illness compared to patients undergoing RP (22.6%; p<0.001). A systematic review of depression and anxiety in patients with PCa identified 27 articles comprising 4,494 patients.8 The meta-analysis of prevalence rates identified pretreatment prevalence of depression of 17.27% (95% confidence interval (CI) 15.06%-19.72%), on-treatment prevalence of 14.70% (95% CI 15.06%-19.72%) and post-treatment prevalence of 18.44% (95% CI 15.18%-22.22%). For anxiety, pretreatment prevalence was 27.04% (95% CI 24.26%-30.01%), on-treatment was 15.09% (95% CI 12.15%-18.60%) and post-treatment was 18.49% (95% CI 13.81%-24.31%). For patients undergoing AS, nearly one-third of patients (29%) report cancer-specific anxiety in the year following diagnosis.9 Interestingly, over time, this anxiety decreased significantly.

There is also increasing evidence that ADT for locally advanced and metastatic PCa is associated with depression. A study from 2016 using SEER-Medicare data found that men that received ADT, compared with patients who did not receive ADT, had higher 3-year cumulative incidences of depression (7.1% v 5.2), inpatient psychiatric treatment (2.8% v 1.9%), and outpatient psychiatric treatment (3.4% v 2.5%).10 Furthermore, the risk of depression increased with the duration of ADT, from 12% with ≤ 6 months of treatment, 26% with 7 to 11 months of treatment, to 37% with ≥ 12 months of treatment. A recent meta-analysis of 18 studies among 168,756 men found that ADT use conferred a 41% increased risk of depression (RR 1.41, 95%CI 1.18-1.70).11 These results were consistent when limiting the analysis to studies in localized disease (relative risk (RR) 1.85, 95%CI 1.20-2.85). Interestingly, this analysis did not find an association for continuous ADT with depression risk compared to intermittent ADT (RR 1.00, 95%CI 0.50-1.99).

Suicidal Risk

Patients with PCa have been shown to be at increased risk of suicide across several population-level studies. In a SEER analysis assessing suicide risk among patients with genitourinary malignancies from 1988-2010, Klaassen et al.12 found an age-adjusted standardized mortality ratio (SMR) of 1.37 for patients with PCa (95%CI, 0.99-1.86) Increasing age, metastatic disease and Caucasian race were risk factors for suicide among these patients. Interestingly, even patients >15 years after diagnosis were at increased risk of suicide compared to the general population (SMR 1.84, 95%CI 1.39-2.41). In an assessment of PCa suicidal risk compared to individuals with other malignancies, Dalela et al.13 found that risk of suicidal death was no different in men with PCa (1,165 [0.2%]) compared to men with other cancers (2,232 [0.2%]), However, within the first year of diagnosis, men with PCa had an increased risk of suicide (absolute risk reduction (ARR) 3.98, 95% CI 3.02-5.23 0-3 months after diagnosis). Furthermore, men with non-metastatic PCa who were Caucasian, uninsured, or recommended but did not receive treatment (hazard ratio (HR) vs treated 1.44, 95%CI 1.20-1.72) were at increased risk of suicidal death.

A meta-analysis of observational studies assessing incidence and risk factors of suicide after PCa diagnosis was recently published.14 This study included 8 observational studies involving 1,281,393 men diagnosed with PCa and 842,294 matched PCa-free men. Guo et al. found an overall increased relative risk of suicide of 2.01 (95% CI 1.52-2.64) among men diagnosed with PCa compared with those without PCa during the first year after diagnosis, particularly during the first 6 months after diagnosis (RR   2.24, 95%CI 1.77-2.85). Additionally, PCa patients were at an increased risk of suicide among men aged 75 years or older (RR  1.51, 95% CI 1.04-2.18) and for those treated with ADT (RR  1.80, 95% CI 1.54-2.12).

Until recently, all population-level studies assessing risk of suicide among PCa patients have not accounted for psychiatric comorbidities at the time of diagnosis. This is important, considering that being unable to adjust for psychiatric comorbidities makes it impossible to assess the true risk associated with a PCa diagnosis on suicidal risk. At the AUA 2019 annual meeting, Klaassen et al.15 presented data assessing all residents of Ontario, Canada diagnosed with either prostate, bladder or kidney cancer (1997-2014). Each patient was assigned a psychiatric utilization gradient (PUG) score in the five years prior to cancer diagnosis: 0 (none), 1 (outpatient), 2 (emergency department), 3 (hospital admission). Non-cancer controls were matched 4:1 to cancer patients based on sociodemographic variables and a marginal cause-specific hazard model was used to assess the effect of cancer on the risk of suicidal death. Among 191,068 patients included (137,699 PCa, 29,884 bladder cancer, 23,485 kidney cancer), 109,154 (57.1%) were PUG score 0, 79,553 (41.6%) PUG score 1, 1,596 (0.84%) PUG score 2, and 765 (0.40%) PUG score 3. Patients with genitourinary cancer had a higher risk of dying of suicide compared to controls (HR 1.16, 95%CI 1.00-1.36). Specifically, among individuals with PUG score 0, those with cancer were significantly more likely to die of suicide compared to patients without cancer (HR 1.39, 95%CI 1.12-1.74).

Guideline Recommendations

The Commission on Cancer requires cancer programs to develop and implement processes to monitor formation and dissemination of a survivorship care plan for all cancer patients with stage I-III disease treated with curative intent, and to have this plan in place within 1-year of diagnosis of cancer and no later than 6 months after completing adjuvant therapy.16 Guideline recommendations for PCa survivorship have primarily been driven by the American Cancer Society (ACS) and the American Society of Clinical Oncology (ASCO). The ACS noted in their 2014 guideline that survivorship should promote comprehensive follow-up care and optimal health and quality of life for the post-treatment PCa survivor.17 The guidelines also address health promotion, surveillance for PCa recurrence, screening for second primary cancers, long-term and late effects assessment and management, psychosocial issues, and care coordination among the oncology team, primary care clinicians, and non-oncology specialists. Subsequently, the ASCO Endorsement Panel reviewed the ACS guidelines, endorsing these guidelines with the following recommendations:18

• Measure PSA level every 6 to 12 months for the first 5 years and then annually, considering more frequent evaluation in men at high risk for recurrence and in candidates for salvage therapy. 

• Refer survivors with elevated or increasing PSA levels back to their primary treating physician for evaluation and management.

• Adhere to ACS guidelines for the early detection of cancer.

• Assess and manage physical and psychosocial effects of PCa and its treatment.

• Annually assess for the presence of long-term or late effects of PCa and its treatment.

Screening Measures

There are several screening tools to assess for quality of life, depression and suicidal risk. A study from 2017 assessed differences in the scores, relative severity and major depressive disorder from three standardized self-report scales for depression in PCa patients [The Hospital Anxiety and Depression Scale Depression subscale (HADS-D), the Self-rating Depression Scale (SDS) and the Patient Health Questionnaire (PHQ-9) for depression].19 Among 138 PCa patients, despite significant correlations between the total scores from the three scales, severity classification differed across the three scales. Furthermore, there was considerable underestimation of depression by the HADS-D compared to the PHQ-9 and a similar tendency for the SDS. This study highlights that scale construction and depression items included can produce different results across scales, making inter-study comparisons difficult. Despite these findings, we recommend that at minimum oncologists should be using at least one depression index to assess patient well-being at each clinic visit.

In addition to the aforementioned HADS-D, SDS, and PHQ-9 metrics, the National Comprehensive Cancer Network (NCCN) provides a guideline for identifying and explaining risk factors in patients with cancer, in addition to providing a “distress thermometer”. The NCCN defines distress, in the setting of cancer, as a multifactorial emotional experience of a psychological, social, and/or spiritual nature that may interfere with the ability to cope effectively with the diagnosis.20 Distress can range from sadness and fear to more disabling symptoms such as anxiety and depression. Furthermore, the time periods at which patients are at increased vulnerability begin with the realization of a suspicious symptom, all the way through to failure/disease recurrence and near the end of life. The NCCN recommends screening all patients for distress to recognize, monitor, and treat patients effectively.20

Previous work has also suggested that screening for depression and erectile dysfunction may be a way to decrease suicidal risk among PCa patients.21 A proposed algorithm allows for an initial evaluation with the EPIC-CP and PHQ-9 tools to assess for health-related quality of life and depression, respectively. If the EPIC-CP or PHQ-9 are negative for depression or erectile dysfunction, these tools should still be used at each visit to regularly evaluate patients. If EPIC-CP or PHQ-9 suggest problems with depression or erectile dysfunction, then an 8-question suicidal ideation questionnaire (adapted from Recklitis et al.22) should be completed. If the suicidal ideation questionnaire demonstrates any level of suicidal ideation, clinicians should make an urgent referral for psychiatric evaluation. This is particularly true when the patient has the concomitant high-risk suicidal risk profile of being elderly, white, single, or with high-risk or disease progression. Given that, at maximum, the patient must answer a 27-point composite questionnaire, this should be feasible in the busy clinical setting and can be provided to the patient at appointment check-in and completed in the waiting room before the physician-patient encounter. Regardless of the results from these screening tools, if any member of the healthcare team has an index of suspicion for suicidal ideation, the physician should immediately make a referral for psychiatric evaluation.

Conclusions

With nearly 3 million men in the United States living with PCa, survivorship programs are now mandated by the Commission on Cancer and play an integral role in health and well-being of men with PCa. In addition to the physical side effects of treatment that should be addressed at each clinic visit, there are crucial psychiatric side effects, including depression, anxiety, and suicidal ideation that should be screened for and recognized by all members of the healthcare team.

Published Date: December 2019
Written by: Zachary Klaassen, MD, MSc
References: 1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin. 2019;69(1):7-34.
2. Hamdy FC, Donovan JL, Lane JA, et al. 10-Year Outcomes after Monitoring, Surgery, or Radiotherapy for Localized Prostate Cancer. N Engl J Med. 2016;375(15):1415-1424.
3. Donovan JL, Hamdy FC, Lane JA, et al. Patient-Reported Outcomes after Monitoring, Surgery, or Radiotherapy for Prostate Cancer. N Engl J Med. 2016;375(15):1425-1437.
4. Albkri A, Girier D, Mestre A, Costa P, Droupy S, Chevrot A. Urinary Incontinence, Patient Satisfaction, and Decisional Regret after Prostate Cancer Treatment: A French National Study. Urol Int. 2018;100(1):50-56.
5. Pinkawa M, Berneking V, Schlenter M, Krenkel B, Eble MJ. Quality of Life After Radiation Therapy for Prostate Cancer With a Hydrogel Spacer: 5-Year Results. Int J Radiat Oncol Biol Phys. 2017;99(2):374-377.
6. Wallis CJ, Mahar AL, Satkunasivam R, et al. Cardiovascular and Skeletal-related Events Following Localized Prostate Cancer Treatment: Role of Surgery, Radiotherapy, and Androgen Deprivation. Urology. 2016;97:145-152.
7. Ravi P, Karakiewicz PI, Roghmann F, et al. Mental health outcomes in elderly men with prostate cancer. Urol Oncol. 2014;32(8):1333-1340.
8. Watts S, Leydon G, Birch B, et al. Depression and anxiety in prostate cancer: a systematic review and meta-analysis of prevalence rates. BMJ Open. 2014;4(3):e003901.
9. Marzouk K, Assel M, Ehdaie B, Vickers A. Long-Term Cancer Specific Anxiety in Men Undergoing Active Surveillance of Prostate Cancer: Findings from a Large Prospective Cohort. J Urol. 2018;200(6):1250-1255.
10. Dinh KT, Reznor G, Muralidhar V, et al. Association of Androgen Deprivation Therapy With Depression in Localized Prostate Cancer. J Clin Oncol. 2016;34(16):1905-1912.
11. Nead KT, Sinha S, Yang DD, Nguyen PL. Association of androgen deprivation therapy and depression in the treatment of prostate cancer: A systematic review and meta-analysis. Urol Oncol. 2017;35(11):664 e661-664 e669.
12. Klaassen Z, Jen RP, DiBianco JM, et al. Factors associated with suicide in patients with genitourinary malignancies. Cancer. 2015;121(11):1864-1872.
13. Dalela D, Krishna N, Okwara J, et al. Suicide and accidental deaths among patients with non-metastatic prostate cancer. BJU Int. 2016;118(2):286-297.
14. Guo Z, Gan S, Li Y, et al. Incidence and risk factors of suicide after a prostate cancer diagnosis: a meta-analysis of observational studies. Prostate Cancer Prostatic Dis. 2018;21(4):499-508.
15. Klaassen Z, Wallis CJ, Goldberg H, et al. Utilization of Psychiatric Resources Prior to Genitourinary (GU) Cancer Diagnosis: Implications for Survival Outcomes. AUA 2019. 2019.
16. Fashoyin-Aje LA, Martinez KA, Dy SM. New patient-centered care standards from the commission on cancer: opportunities and challenges. J Support Oncol. 2012;10(3):107-111.
17. Skolarus TA, Wolf AM, Erb NL, et al. American Cancer Society prostate cancer survivorship care guidelines. CA Cancer J Clin. 2014;64(4):225-249.
18. Resnick MJ, Lacchetti C, Bergman J, et al. Prostate cancer survivorship care guideline: American Society of Clinical Oncology Clinical Practice Guideline endorsement. J Clin Oncol. 2015;33(9):1078-1085.
19. Sharpley CF, Bitsika V, Christie DR, Hunter MS. Measuring depression in prostate cancer patients: does the scale used make a difference? Eur J Cancer Care (Engl). 2017;26(1).
20. National Comprehensive Cancer N. Distress management. Clinical practice guidelines. J Natl Compr Canc Netw. 2003;1(3):344-374.
21. Klaassen Z, Arora K, Wilson SN, et al. Decreasing suicide risk among patients with prostate cancer: Implications for depression, erectile dysfunction, and suicidal ideation screening. Urol Oncol. 2018;36(2):60-66.
22. Recklitis CJ, Zhou ES, Zwemer EK, Hu JC, Kantoff PW. Suicidal ideation in prostate cancer survivors: understanding the role of physical and psychological health outcomes. Cancer. 2014;120(21):3393-3400.

Mapping Progress in Bladder Cancer

For those of us who take care of patients with the sixth most common malignancy in the United States and the seventh most common cause of cancer-related death,1 it was disheartening that, as recently as 2015, patients with advanced bladder cancer had no effective alternatives to cisplatinum-based chemotherapy, a status quo that had persisted for three decades.2
Written by: Ashish Kamat, MD, MBBS
References:
  1. National Cancer Institute. Cancer Stat Facts: Bladder Cancer. https://seer.cancer.gov/statfacts/html/urinb.html Accessed January 15, 2019.
  2. Hermans TJN, Voskuilen CS, van der Heijden MS, et al. Neoadjuvant treatment for muscle-invasive bladder cancer: The past, the present, and the future. Urol Oncol 2018 Sep;36(9):413-422.
  3. Kamat AM et al. BCG-unresponsive non-muscle-invasive bladder cancer: recommendations from the IBCG. Nat Rev Urol. 2017 Apr;14(4):244-255.
  4. Bellmunt J, de Wit R, Vaughn DJ, et al. Pembrolizumab as second-line therapy for advanced urothelial carcinoma. N Engl J Med 2017 Mar;376(11):1015-1026.
  5. Patel MR, Ellerton J, Infante JR, et al. Avelumab in metastatic urothelial carcinoma after platinum failure (JAVELIN Solid Tumor): pooled results from two expansion cohorts of an open-label, phase 1 trial. Lancet Oncol 2018 Jan;19(1):51-64.
  6. Powles T, O'Donnell PH, Massard C, et al. Efficacy and safety of durvalumab in locally advanced or metastatic urothelial carcinoma: Updated results from a phase 1/2 open-label study. JAMA Oncol 2017;3(9):e172411.
  7. Rosenberg JE, Hoffman-Censits J, Powles T, et al. Atezolizumab in patients with locally advanced and metastatic urothelial carcinoma who have progressed following treatment with platinum-based chemotherapy: a single-arm, multicentre, phase 2 trial. Lancet 2016 May 7;387(10031):1909-1920.
  8. Sharma P, Retz M, Siefker-Radtke A, et al. Nivolumab in metastatic urothelial carcinoma after platinum therapy (CheckMate 275): a multicentre, single-arm, phase 2 trial. TLancet Oncol 2017 Mar;18(3):312-322.
  9. Rosenberg JE, Sridhar SS, Zhang J, et al. Updated results from the enfortumab vedotin phase 1 (EV-101) study in patients with metastatic urothelial cancer (mUC). J Clin Oncol 2018 May;36(15_suppl):4504-4504.
  10. Siefker-Radtke AO, Necchi A, Park SH, et al. First results from the primary analysis population of the phase 2 study of erdafitinib (ERDA; JNJ-42756493) in patients (pts) with metastatic or unresectable urothelial carcinoma (mUC) and FGFR alterations (FGFRalt). J Clin Oncol 2018 May;36(15_suppl):4503-4503.
  11. Hahn, NM. A Golden Age of Bladder Cancer Drug Development. Urotoday.com

Updates in Systemic Therapy for Upper Tract Urothelial Carcinoma: Perioperative Considerations

In this article, we will discuss data for the use of systemic therapy in upper tract urothelial carcinoma with a focus on perioperative systemic therapy.
Until recently, there have been very limited randomized data to guide the provision of perioperative systemic therapy in upper tract urothelial carcinoma. Thus, data has been extrapolated from patients with urothelial carcinoma of the bladder.

Neoadjuvant therapy

Data for the use of neoadjuvant chemotherapy prior to radical cystectomy in urothelial carcinoma of the bladder are robust: the Advanced Bladder Cancer meta-analysis collaboration, in a meta-analysis of 11 trials with 3,005 patients, demonstrated a significant survival benefit to the use of neoadjuvant platinum-based combination chemotherapy as compared to upfront surgery (hazard ratio 0.86, 95% confidence interval 0.77 to 0.95). In absolute terms, this corresponds to a 5% absolute survival at 5 years.5

In contrast, there is extremely limited data regarding the use of neoadjuvant chemotherapy in patients with upper tract urothelial carcinoma. No institution has published data on more than 50 patients who received neoadjuvant chemotherapy prior to nephroureterectomy. In two publications, the MD Anderson Cancer Center group has reported on their experience. Matin et al. reported on 43 patients with biopsy-proven high-grade upper tract urothelial carcinoma who underwent neoadjuvant chemotherapy prior to nephroureterectomy.6 They demonstrated a 14% pathologic complete response rate in this cohort. Additionally, when compared to historical controls, there was an increased likelihood of downstage (p=0.004): pT2 disease was found in 49% compared with 65% in controls and pT3 disease was found in 28% compared with 48%. In a more recent analysis, Porten et al. provided a retrospective review of 31 patients who underwent neoadjuvant chemotherapy prior to nephroureterectomy compared to 81 historical controls who received initial surgery for high-risk upper tract urothelial carcinoma.7 They demonstrated that patients receiving neoadjuvant chemotherapy had improved five year overall survival (80% versus 58%, p=0.02) and five year disease-specific survival (90% versus 58%, p=0.002). After adjusting for relevant patient, treatment and tumor characteristics, the risk of overall mortality (hazard ratio 0.42, p=0.035) and disease-specific mortality (hazard ratio 0.19, p=0.006) were significantly lower among patients who received neoadjuvant therapy.

More recently, Kubota and colleagues reported a multi-institutional analysis of 101 patients with high-risk upper tract urothelial carcinoma (stage cT3-4 or cN+) who received neoadjuvant chemotherapy prior to nephroureterectomy at 5 medical centers in Japan and compared these to 133 patients who received surgery alone.8 Most patients who received neoadjuvant chemotherapy in this cohort were given gemcitabine and carboplatin (75%) while a minority received gemcitabine and cisplatin (21%). The authors found that while neoadjuvant chemotherapy increased pathological downstaging and was independently predictive of improved recurrence-free survival and cancer-specific survival, they were unable to demonstrate improvements in overall survival.

Finally, in 2018, Liao et al reported their experience from Johns Hopkins.9 They compared 32 patients who received neoadjuvant chemotherapy prior to nephroureterectomy for biopsy-proven high-grade upper tract urothelial carcinoma to 208 patients who underwent surgery alone. These authors found a 9.4% pathologic complete response rate in addition to significant pathologic downstaging.

In comparison to the use of neoadjuvant chemotherapy for urothelial carcinoma of the bladder, there is potentially even greater rationale for its use in upper tract urothelial carcinoma. First, patients are much more likely to be able to tolerate a highly efficacious regime (gemcitabine and cisplatin) with two functioning kidneys prior to nephroureterectomy than they will post-operatively. Additionally, important prognostic information can be derived if patients experience pathological downstaging.1 However, one of the primary barriers to the use of neoadjuvant chemotherapy is the lack of reliable pre-operative pathologic specimens to identify invasive disease, as mentioned previously. Second, there are concerns regarding the delay to definitive surgical treatment, particularly in patients who may have chemoresistant disease. Third, there are concerns regarding a potential increase in perioperative morbidity.

Finally, there is a concern of overtreatment through the use of toxic medications in patients who may or may not have invasive disease. There have been attempts to assess the role of neoadjuvant chemotherapy in this patient population. A trial from the University of Michigan was terminated due to poor accrual (NCT01663285). Memorial Sloan Kettering is a sponsor for a trial of gemcitabine and cisplatin as neoadjuvant chemotherapy in patients with upper tract urothelial carcinoma, which according to the last update remains active but is no longer recruiting. This trial sought to enroll 57 participants in a Phase II design to assess the primary outcome of pathological response rate. Additionally, a Phase II ECOG-ACRIN trial seeking to assess pathologic complete response rates following neoadjuvant chemotherapy (MVAC or gemcitabine and cisplatin) among 36 patients with high-grade upper tract urothelial carcinoma. Results have not yet been published though they were presented at AUA 2018. While the gemcitabine and cisplatin arm did not meet accrual, 30 patients were accrued to the ddMVAC arm. Pathologic complete response was seen in 6 of 29 evaluable patients. None of these trials have provided a randomized comparison to surgery alone. In contrast, NCT02876861 is a trial from Xiangya Hospital of Central South University which is actively recruiting patients and randomizing to neoadjuvant chemotherapy with gemcitabine and cisplatin prior to nephroureterectomy or surgery alone. They are targeting accrual of 50 patients to assess the primary outcome of disease-free survival.

Adjuvant chemotherapy

Again, there is strong evidence for adjuvant chemotherapy in urothelial carcinoma of the bladder. In contrast to neoadjuvant chemotherapy, the data for adjuvant chemotherapy in upper tract urothelial carcinoma are more robust.

First, there is a meta-analysis of nine retrospective cohort studies comparing 482 patients who received adjuvant chemotherapy to 1,300 patients who were treated with surgery alone. Those who received adjuvant therapy had significantly improved disease-free survival (hazard ratio 0.49, 95% confidence interval 0.24 to 0.99) and overall survival (hazard ratio 0.43, 95% confidence interval 0.21 to 0.89)10. This analysis is limited by significant selection biases.

In contrast, a Phase III randomized trial of perioperative chemotherapy versus surveillance in upper tract urothelial cancer (POUT) is a Phase III, multicenter trial from the Institute of Cancer Research in the United Kingdom which randomized patients who are chemotherapy eligible with pT2-4, pN0-3 or pT1, pN+ following nephroureterectomy to adjuvant platinum-based chemotherapy or surveillance. The results of this trial remain to be published, although they have been presented at ASCO GU and EAU in 2018. To summarize, 123 patients were randomized to surveillance and 125 to adjuvant chemotherapy at 57 different centers. Patients in the intervention arm received either gemcitabine and cisplatin or gemcitabine and carboplatin as their renal function allowed. The majority of enrolled patients had pT3 disease (65%) and were node-negative (pN0, 91%). The authors demonstrated that adjuvant chemotherapy significantly improved disease-free survival (hazard ratio 0.49, 95% confidence interval 0.31 to 0.76) as well as metastasis-free survival (hazard ratio 0.49, 95% confidence interval 0.30 to 0.79). However, overall survival data were not yet mature at the time of presentation, so despite the separation of the curves, a meaningful benefit cannot be shown yet. Grade 3 or greater toxicity was experienced by 60% of patients receiving adjuvant chemotherapy and 24% of patients undergoing surveillance.

Previous analyses have demonstrated that patients are much less likely to derive benefit from non-cisplatin based regimes10. Thus, a significant decline in renal function attributable to nephroureterectomy may result in many patients being unable to receive optimal systemic therapy.

Immunotherapy

The data discussed this far center on the use of cytotoxic chemotherapy, whether gemcitabine and cisplatin, MVAC, or gemcitabine and carboplatin, as these have been the traditional agents used for patients with urothelial carcinoma. Following data supporting the role of immunotherapy using checkpoint inhibitors in patients with advanced metastatic urothelial carcinoma, the recently published Phase II PURE-01 trial examined neoadjuvant pembrolizumab for muscle-invasive urothelial bladder carcinoma11. This analysis demonstrated higher rates of pathologic complete response (42%) and downstaging to non-muscle invasive disease (54%) than would be expected from historical use of cytotoxic chemotherapy, though a randomized control was not employed in this analysis. Analyses of durvalumab plus tremelimumab and of gemcitabine plus cisplatin plus pembrolizumab demonstrated similarly promising results. This approach has not, to our knowledge, been tested in upper tract urothelial carcinoma but such an approach may be particularly valuable in these patients.

Conclusions

At the 2018 Society of Urologic Oncology meeting, Dr. Jean Hoffman-Censits presented on the role of neoadjuvant chemotherapy in these patients. She discussed differences between urothelial carcinomas of the bladder and of the upper urinary tract. Notably, she highlighted that pathologic response rates appear to be lower in patients with upper tract urothelial carcinoma (9-15%) as compared to bladder cancer (>20%). The ongoing URANUS trial will better delineate the role of neoadjuvant therapy in upper tract urothelial carcinoma.

Published Date: December 2019
Written by: Zachary Klaassen, MD, MSc
References: 1. Leow JJ, Chong KT, Chang SL, et al. Upper tract urothelial carcinoma: a different disease entity in terms of management. ESMO Open 2016; 1(6):e000126.
2. Catto JW, Azzouzi AR, Amira N, et al. Distinct patterns of microsatellite instability are seen in tumours of the urinary tract. Oncogene 2003; 22(54):8699-706.
3. Kunze E, Wendt M, Schlott T. Promoter hypermethylation of the 14-3-3 sigma, SYK and CAGE-1 genes is related to the various phenotypes of urinary bladder carcinomas and associated with progression of transitional cell carcinomas. Int J Mol Med 2006; 18(4):547-57.
4. Margulis V, Shariat SF, Matin SF, et al. Outcomes of radical nephroureterectomy: a series from the Upper Tract Urothelial Carcinoma Collaboration. Cancer 2009; 115(6):1224-33.
5. Advanced Bladder Cancer Meta-analysis C. Neoadjuvant chemotherapy in invasive bladder cancer: update of a systematic review and meta-analysis of individual patient data advanced bladder cancer (ABC) meta-analysis collaboration. Eur Urol 2005; 48(2):202-5; discussion 205-6.
6. Matin SF, Margulis V, Kamat A, et al. Incidence of downstaging and complete remission after neoadjuvant chemotherapy for high-risk upper tract transitional cell carcinoma. Cancer 2010; 116(13):3127-34.
7. Porten S, Siefker-Radtke AO, Xiao L, et al. Neoadjuvant chemotherapy improves survival of patients with upper tract urothelial carcinoma. Cancer 2014; 120(12):1794-9.
8. Kubota Y, Hatakeyama S, Tanaka T, et al. Oncological outcomes of neoadjuvant chemotherapy in patients with locally advanced upper tract urothelial carcinoma: a multicenter study. Oncotarget 2017; 8(60):101500-101508.
9. Liao RS, Gupta M, Schwen ZR, et al. Comparison of Pathological Stage in Patients Treated with and without Neoadjuvant Chemotherapy for High Risk Upper Tract Urothelial Carcinoma. J Urol 2018; 200(1):68-73.
10. Leow JJ, Martin-Doyle W, Fay AP, et al. A systematic review and meta-analysis of adjuvant and neoadjuvant chemotherapy for upper tract urothelial carcinoma. Eur Urol 2014; 66(3):529-41.
11. Necchi A, Anichini A, Raggi D, et al. Pembrolizumab as Neoadjuvant Therapy Before Radical Cystectomy in Patients With Muscle-Invasive Urothelial Bladder Carcinoma (PURE-01): An Open-Label, Single-Arm, Phase II Study. J Clin Oncol 2018:JCO1801148.

A Golden Age of Bladder Cancer Drug Development

Recent years have seen an explosive rate of transformative advances in both pre-clinical and clinical urothelial carcinoma research.  With the public dissemination of comprehensive molecular data from The Cancer Genome Atlas (TCGA) urothelial carcinoma cohort, the global urothelial carcinoma research community now has the initial road map of the key biological themes that drive carcinogenesis, growth, invasion, and metastasis.1 
Written by: Noah M. Hahn, MD
References:
  1. Comprehensive molecular characterization of urothelial bladder carcinoma. Nature 507:315-22, 2014
  2. Bellmunt J, de Wit R, Vaughn DJ, et al: Pembrolizumab as Second-Line Therapy for Advanced Urothelial Carcinoma. N Engl J Med 376:1015-1026, 2017
  3. Patel MR, Ellerton J, Infante JR, et al: Avelumab in metastatic urothelial carcinoma after platinum failure (JAVELIN Solid Tumor): pooled results from two expansion cohorts of an open-label, phase 1 trial. Lancet Oncol 19:51-64, 2018
  4. Powles T, O'Donnell PH, Massard C, et al: Efficacy and safety of durvalumab in locally advanced or metastatic urothelial carcinoma: Updated results from a phase 1/2 open-label study. JAMA Oncology 3:e172411, 2017
  5. Rosenberg JE, Hoffman-Censits J, Powles T, et al: Atezolizumab in patients with locally advanced and metastatic urothelial carcinoma who have progressed following treatment with platinum-based chemotherapy: a single-arm, multicentre, phase 2 trial. The Lancet 387:1909-1920, 2016
  6. Sharma P, Retz M, Siefker-Radtke A, et al: Nivolumab in metastatic urothelial carcinoma after platinum therapy (CheckMate 275): a multicentre, single-arm, phase 2 trial. The Lancet Oncology 18:312-322, 2017
  7. Rosenberg JE, Sridhar SS, Zhang J, et al: Updated results from the enfortumab vedotin phase 1 (EV-101) study in patients with metastatic urothelial cancer (mUC). Journal of Clinical Oncology 36:4504-4504, 2018
  8. Siefker-Radtke AO, Necchi A, Park SH, et al: First results from the primary analysis population of the phase 2 study of erdafitinib (ERDA; JNJ-42756493) in patients (pts) with metastatic or unresectable urothelial carcinoma (mUC) and FGFR alterations (FGFRalt). J Clin Oncol 36, 2018

Bone-Targeted Therapy in Prostate Cancer

Zoledronic acid

To maintain bone integrity during bone remodeling, homeostasis of osteoblasts increasing bone mass and osteoclasts resorbing bone is required. Bisphosphonates are rapidly absorbed on the bone surface and inhibit osteoclast activity by affecting cytoskeletal dynamics. The Phase III Zoledronic acid 039 trial showed that among men with metastatic castration-resistant prostate cancer (mCRPC), a greater proportion of patients who received placebo had skeletal-related events than those who received zoledronic acid at 4 mg (44.2% versus 33.2%, p =0.021) or those who received zoledronic acid at 8 mg (38.5%, p = 0.222
Written by: Zachary Klaassen, MD, MSc
References: 1. Norgaard M, Jensen AO, Jacobsen JB, Cetin K, Fryzek JP, Sorensen HT. Skeletal related events, bone metastasis and survival of prostate cancer: a population based cohort study in Denmark (1999 to 2007). J Urol. 2010;184(1):162-167.
2. Gartrell BA, Coleman R, Efstathiou E, et al. Metastatic Prostate Cancer and the Bone: Significance and Therapeutic Options. Eur Urol. 2015;68(5):850-858.
3. Klaassen Z, Howard LE, de Hoedt A, et al. Factors predicting skeletal-related events in patients with bone metastatic castration-resistant prostate cancer. Cancer. 2017;123(9):1528-1535.
4. Saad F, Gleason DM, Murray R, et al. A randomized, placebo-controlled trial of zoledronic acid in patients with hormone-refractory metastatic prostate carcinoma. J Natl Cancer Inst. 2002;94(19):1458-1468.
5. Smith MR, Halabi S, Ryan CJ, et al. Randomized controlled trial of early zoledronic acid in men with castration-sensitive prostate cancer and bone metastases: results of CALGB 90202 (alliance). J Clin Oncol. 2014;32(11):1143-1150.
6. Fizazi K, Carducci M, Smith M, et al. Denosumab versus zoledronic acid for treatment of bone metastases in men with castration-resistant prostate cancer: a randomised, double-blind study. Lancet. 2011;377(9768):813-822.
7. Smith MR, Saad F, Oudard S, et al. Denosumab and bone metastasis-free survival in men with nonmetastatic castration-resistant prostate cancer: exploratory analyses by baseline prostate-specific antigen doubling time. J Clin Oncol. 2013;31(30):3800-3806.
8. Heidenreich A, Bastian PJ, Bellmunt J, et al. EAU guidelines on prostate cancer. Part II: Treatment of advanced, relapsing, and castration-resistant prostate cancer. Eur Urol. 2014;65(2):467-479.
9. Parker C, Nilsson S, Heinrich D, et al. Alpha emitter radium-223 and survival in metastatic prostate cancer. N Engl J Med. 2013;369(3):213-223.
10. Smith M, Parker C, Saad F, et al. Addition of radium-223 to abiraterone acetate and prednisone or prednisolone in patients with castration-resistant prostate cancer and bone metastases (ERA 223): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol. 2019;20(3):408-419.
11. Vignani F, Bertaglia V, Buttigliero C, Tucci M, Scagliotti GV, Di Maio M. Skeletal metastases and impact of anticancer and bone-targeted agents in patients with castration-resistant prostate cancer. Cancer Treat Rev. 2016;44:61-73.
12. Basch E, Autio KA, Smith MR, et al. Effects of cabozantinib on pain and narcotic use in patients with castration-resistant prostate cancer: results from a phase 2 nonrandomized expansion cohort. Eur Urol. 2015;67(2):310-318.
13. Araujo JC, Mathew P, Armstrong AJ, et al. Dasatinib combined with docetaxel for castration-resistant prostate cancer: results from a phase 1-2 study. Cancer. 2012;118(1):63-71.
14. Araujo JC, Trudel GC, Saad F, et al. Docetaxel and dasatinib or placebo in men with metastatic castration-resistant prostate cancer (READY): a randomised, double-blind phase 3 trial. Lancet Oncol. 2013;14(13):1307-1316.
15. Nelson JB. Endothelin receptor antagonists. World J Urol. 2005;23(1):19-27.
16. Nelson JB, Love W, Chin JL, et al. Phase 3, randomized, controlled trial of atrasentan in patients with nonmetastatic, hormone-refractory prostate cancer. Cancer. 2008;113(9):2478-2487.

Malignant Renal Tumors

Renal cancers are common, accounting for an estimated 65,340 new diagnoses and 14,970 attributable deaths in 2018 in the United States.1 In the article, "Epidemiology and Etiology of Kidney Cancer" both topics are discussed at great length. Despite a large number of histologic tumors which may occur in the kidney, renal cell carcinoma (RCC) is the most prevalent histology.

Tumor biology

Research into the molecular genetics of hereditary RCC has yielded many insights which contribute to the treatment of sporadic RCCs. An understanding of the function of the von Hippel Lindau protein led to the identification of the importance of vascular endothelial growth factor (VEGF) and the mammalian target of rapamycin (mTOR) pathways. Identification of the importance of VEGF aided in both explaining the significant neovascularity associated with ccRCC and providing a therapeutic target for systemic therapy.

Other molecular insights have significant clinical implications as well. First, RCC expresses multi-drug resistance proteins, energy-dependent efflux pumps. These pumps prevent the intracellular accumulation of chemotherapeutics and contribute to the chemotherapy-resistance of RCC. Second, based on observations of tumor-infiltrating immune cells and neoantigens, RCC is highly immunogenic. Thus, immunotherapies beginning with interleukins and interferon and now immune checkpoint inhibitors are efficacious in RCC.

Unfortunately, none of these insights have to lead to validated diagnostic, prognostic, or predictive biomarkers to date.

Pathology

Renal cell carcinoma tends to form relatively spherical tumors with a surrounding pseudo capsule of compressed adjacent parenchyma and fibrosis. With rare exceptions (collecting duct carcinoma and sarcomatoid variants), RCC tends to be relatively well circumscribed without gross infiltrative features. This allows for local treatment, radiographically-guided approaches such as partial nephrectomy and tumor ablation (see linked article on non-surgical focal therapy of renal tumors). Grading of RCC is undertaken using Fuhrman’s system. While this approach was developed for ccRCC,2 more recent evidence suggests that it is prognostic in papillary RCC as well.3 Fuhrman’s grading system relies on the size and shape of the nucleus and the presence or absence of nucleoli.

table-1-malignant-renal-tumors@2x.jpg


A relatively unique pathological characteristic of RCC is its propensity for the involvement of the venous system. This occurs in nearly 10% of all RCCs, at least in historical series, which is much higher than other tumor types.4

Histologic subgroups

A number of histological subtypes have been recognized including conventional clear cell RCC (ccRCC), papillary RCC, chromophobe RCC, collecting duct carcinoma, renal medullary carcinoma, unclassified RCC, RCC associated with Xp11.2 translocations/TFE3 gene fusions, post-neuroblastoma RCC, and mucinous tubular and spindle cell carcinoma. Conventional ccRCC comprises approximately 70-80% of all RCCs while papillary RCC comprises 10-15%, chromophobe 3-5%, collecting duct carcinoma <1%, unclassified RCC 1-3%, and the remainder are very uncommon.

Clear cell RCC is formerly described as “conventional” RCC. These tumors, as mentioned prior, are highly vascular and thus tend to respond well to vascular-targeted agents when systemic therapy is indicated. In general, ccRCC is more aggressive than papillary RCC or chromophobe RCC, even after accounting for stage and grade.5

Papillary RCC, formerly known as “chromophilic” RCC, may be subdivided into type 1 and type 2. Type 1 papillary RCC histologically is characterized by basophilic cells with low-grade nuclei. In contrast, type 2 papillary RCC has eosinophilic cells with high-grade nuclei. Correspondingly, type 1 papillary RCC is less aggressive and portends a more favourable prognosis than type 2 papillary RCC. Papillary RCC exhibits a predilection for multifocality.

Chromophobe RCC is histologically characterized by a perinuclear halo. While chromophobe RCC typically have a good prognosis, those with sarcomatoid features are associated with a poor outcome.6

Collecting duct carcinoma and renal medullary carcinoma are relatively rare variants of RCC which exhibit aggressive behaviour and have poor to dismal prognosis. Renal medullary carcinoma is notably found in patients with sickle cell trait.

Finally, rather than its prior classification as a distinct subtype, sarcomatoid differentiation is now noted as a feature accompanying an underlying histologic characterization.

Clinical presentation of RCC

Historically, RCC was diagnosed on the basis of a classic triad of flank pain, gross hematuria, and a palpable flank mass. However, nowadays most RCCs are diagnosed incidentally during abdominal imaging for a variety of nonspecific abdominal complaints.7 Symptoms may arise due to local tumor growth, hemorrhage, paraneoplastic syndromes, or metastatic disease.

While paraneoplastic syndromes are relatively uncommon in other tumors, these occur in 10-20% of patients with RCC. A wide variety of clinical manifestations due to endocrinologically-active compounds may occur including hypertension, electrolyte dysregulation, and cytokine-driven effects such as weight loss, fever, and anemia.

Screening for RCC

Due in large part to the relatively low incidence of RCC, widespread screening is not advocated.

However, certain populations at a much higher risk of RCC warrant screening. This including patients with end-stage renal disease and acquired renal cystic disease, those with tuberous sclerosis, and those with familial RCC syndromes. Patients with end-stage renal disease are generally recommended to undergo RCC screening upon reaching their third year on dialysis assuming that they do not have other major comorbidities which would be life-limiting.

Staging of RCC

Robson’s staging system was widely used until the 1990s. However, there are numerous limitations including the amalgamation of tumors with lymph node metastases and those with venous involvement as stage III and the omission of tumor size. Thus, the TNM (tumor, node, metastasis) system is now widely used.


table-2-malignant-renal-tumors@2x.jpg


Notably, the involvement of the ipsilateral adrenal gland may be classified at T4 if contiguous or M1 if metastatic. Historically, lymph node involvement had been sub-stratified. However, this did not show the prognostic value. Thus, a single present/absent classification is now used.

As may be implied from the characteristics used in the staging schema, clinical staging involves a thorough history, physical examination, radiographic investigation and laboratory investigations (including liver function tests). Contrast-enhanced abdominal computed tomography and chest radiograph are considered standard imaging approaches.8 MRI may be indicated in patients with locally advanced disease, those with unclear venous involvement, and those for whom CT is contraindicated.8 For patients with suspected inferior vena cava involvement, MRI or multiplanar CT are reasonable imaging approaches.8 Doppler ultrasonography is an alternative. Venacavography is rarely utilized today. In patients with suspected metastatic disease, bone scintigraphy is indicated among those with elevated serum alkaline phosphate, bony pain, or poor performance status.9 Similarly, CT chest is indicated in patients with pulmonary symptoms or an abnormal chest radiograph.

A number of prognostic factors have been described for patients with RCC:10
  1. Clinical characteristics:
    1. Performance status
    2. Systemic symptoms
    3. Symptomatic (vs. incidental) presentation
    4. Anemia
    5. Thrombocytosis
    6. Hypercalcemia
    7. Elevated lactate dehydrogenase
    8. Elevated erythrocyte sedimentation rate
    9. Elevated C-reactive protein
    10. Elevated alkaline phosphatase
  2. Tumor anatomic characteristics:
    1. Tumor size
    2. Venous extension
    3. Contiguous invasion of adjacent organs (i.e. T4 stage)
    4. Adrenal involvement (i.e. T4 or M1 stage)
    5. Lymph node metastasis (i.e. N1 stage)
    6. Presence and burden of metastatic disease (i.e. M1 stage)
  3. Tumor histologic characteristics:
    1. Histologic subtype
    2. Presence of sarcomatoid differentiation
    3. Nuclear grade
    4. Presence of histologic necrosis
    5. Vascular invasion
    6. Invasion of perinephric or sinus fat
    7. Invasion of collecting system
    8. (post-operative) surgical margin status
Pathologic stage is the single most important prognostic factor in RCC.10 Interestingly, tumor size has additional independent prognostic value, beyond that which is conveyed in the tumor stage.11 Among patients with IVC thrombus, direct invasion into the caval wall appears to portend a worse prognosis.12

To date, no biomarkers have been adopted in clinical practice for prognostic or predictive purposes. However, a number of nomograms relying on clinical data have been proposed for risk prediction. They may be useful in predicting tumor histology, recurrence rates, and survival.

Treatment of RCC (localized)

There are a number of accepted treatment options for patients diagnosed with localized RCC. These include radical nephrectomy (whether open, laparoscopic or robotic), partial nephrectomy (whether open, laparoscopic, or robotic), surgical or non-surgical ablation, and active surveillance. The most appropriate treatment strategy will depend on the patient (host) and tumor characteristics.

The ability to distinguish between benign and malignant renal masses is relatively limited on the basis of clinical characteristics. The renal mass biopsy may, therefore, be indicated where the results of this test would modify treatment choices.

Radical nephrectomy was historically the treatment of choice for localized RCC. Partial nephrectomy was initially indicated for patients with imperative indications. However, today, partial nephrectomy is the standard of care for small renal masses. Radical nephrectomy remains indicated for patients with larger tumors and those where partial nephrectomy is not feasible (for example, a tumor in a very central location).13 The primary concern regarding radical nephrectomy is the loss of nephron mass and the corresponding risk of surgically induced chronic kidney disease (CKD). Such CKD may predispose to cardiovascular events and premature mortality. However, the only randomized controlled trial to compare radical and partial nephrectomy (EORTC 30904) demonstrated improved overall survival among patients undergoing radical nephrectomy and decreased rates of cardiovascular events.14 These results have proven controversial and have not dissuaded enthusiasm for partial nephrectomy.

A more fulsome discussion regarding nonsurgical renal mass ablation may be found entitled “Focal therapy for renal tumors.”

Finally, active surveillance has gained acceptance. This approach was first employed among asymptomatic elderly patients who were poor surgical candidates with small, incidentally detected RCCs.15 Subsequent follow-up has demonstrated that small renal masses grow quite slowly (0.1-0.3cm/year). AUA guidelines recommend serial abdominal imaging to both ascertain the growth and monitor for progression.16 Biopsy may be considered in order to inform surveillance strategies. For patients found to have biopsy-proven RCC, a chest radiograph may be added to the annual surveillance testing.

The American Urological Association offers a helpful algorithm to guide treatment decision making in patients with small renal masses

Published Date: April 16th, 2019
References:
  1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2018. CA: a cancer journal for clinicians 2018;68:7-30.
  2. Fuhrman SA, Lasky LC, Limas C. Prognostic significance of morphologic parameters in renal cell carcinoma. Am J Surg Pathol 1982;6:655-63.
  3. Sukov WR, Lohse CM, Leibovich BC, Thompson RH, Cheville JC. Clinical and pathological features associated with prognosis in patients with papillary renal cell carcinoma. The Journal of urology 2012;187:54-9.
  4. Skinner DG, Pfister RF, Colvin R. Extension of renal cell carcinoma into the vena cava: the rationale for aggressive surgical management. The Journal of urology 1972;107:711-6.
  5. Deng FM, Melamed J. Histologic variants of renal cell carcinoma: does tumor type influence outcome? The Urologic clinics of North America 2012;39:119-32.
  6. Klatte T, Han KR, Said JW, et al. Pathobiology and prognosis of chromophobe renal cell carcinoma. Urologic oncology 2008;26:604-9.
  7. Almassi N, Gill BC, Rini B, Fareed K. Management of the small renal mass. Transl Androl Urol 2017;6:923-30.
  8. Ng CS, Wood CG, Silverman PM, Tannir NM, Tamboli P, Sandler CM. Renal cell carcinoma: diagnosis, staging, and surveillance. AJR Am J Roentgenol 2008;191:1220-32.
  9. Shvarts O, Lam JS, Kim HL, Han KR, Figlin R, Belldegrun A. Eastern Cooperative Oncology Group performance status predicts bone metastasis in patients presenting with renal cell carcinoma: implication for preoperative bone scans. The Journal of urology 2004;172:867-70.
  10. Lane BR, Kattan MW. Prognostic models and algorithms in renal cell carcinoma. The Urologic clinics of North America 2008;35:613-25; vii.
  11. Kattan MW, Reuter V, Motzer RJ, Katz J, Russo P. A postoperative prognostic nomogram for renal cell carcinoma. The Journal of urology 2001;166:63-7.
  12. Zini L, Destrieux-Garnier L, Leroy X, et al. Renal vein ostium wall invasion of renal cell carcinoma with an inferior vena cava tumor thrombus: prediction by renal and vena caval vein diameters and prognostic significance. The Journal of urology 2008;179:450-4; discussion 4.
  13. Nguyen CT, Campbell SC, Novick AC. Choice of operation for clinically localized renal tumor. The Urologic clinics of North America 2008;35:645-55; vii.
  14. Van Poppel H, Da Pozzo L, Albrecht W, et al. A prospective, randomised EORTC intergroup phase 3 study comparing the oncologic outcome of elective nephron-sparing surgery and radical nephrectomy for low-stage renal cell carcinoma. European urology 2011;59:543-52.
  15. Abouassaly R, Lane BR, Novick AC. Active surveillance of renal masses in elderly patients. The Journal of urology 2008;180:505-8; discussion 8-9.
  16. Donat SM, Diaz M, Bishoff JT, et al. Follow-up for Clinically Localized Renal Neoplasms: AUA Guideline. The Journal of urology 2013;190:407-16.

Adjuvant Systemic Therapy for High Risk Kidney Cancer

Adjuvant targeted therapy

Tyrosine kinase inhibitors (TKIs) quickly became standard of care for patients with metastatic renal cell carcinoma following their introduction in the early 2000s. They have subsequently been investigated as adjuvant therapy in 4 published randomized trials to our knowledge. In addition, the SORCE trial was presented at ESMO 2019 at the end of September 2019.

Written by: Zachary Klaassen, MD, MSc
References: 1. Patel HD, Gupta M, Joice GA, et al. Clinical Stage Migration and Survival for Renal Cell Carcinoma in the United States. Eur Urol Oncol 2019; 2(4):343-348
2. Haas NB, Manola J, Uzzo RG, et al. Adjuvant sunitinib or sorafenib for high-risk, non-metastatic renal-cell carcinoma (ECOG-ACRIN E2805): a double-blind, placebo-controlled, randomised, phase 3 trial. Lancet 2016; 387(10032):2008-16.
3. Motzer RJ, Haas NB, Donskov F, et al. Randomized Phase III Trial of Adjuvant Pazopanib Versus Placebo After Nephrectomy in Patients With Localized or Locally Advanced Renal Cell Carcinoma. J Clin Oncol 2017; 35(35):3916-3923.
4. Ravaud A, Motzer RJ, Pandha HS, et al. Adjuvant Sunitinib in High-Risk Renal-Cell Carcinoma after Nephrectomy. N Engl J Med 2016; 375(23):2246-2254.
5. Gross-Goupil M, Kwon TG, Eto M, et al. Axitinib versus placebo as an adjuvant treatment of renal cell carcinoma: results from the phase III, randomized ATLAS trial. Ann Oncol 2018; 29(12):2371-2378.
6. Haas NB, Manola J, Dutcher JP, et al. Adjuvant Treatment for High-Risk Clear Cell Renal Cancer: Updated Results of a High-Risk Subset of the ASSURE Randomized Trial. JAMA Oncol 2017; 3(9):1249-1252
7. Sun M, Marconi L, Eisen T, et al. Adjuvant Vascular Endothelial Growth Factor-targeted Therapy in Renal Cell Carcinoma: A Systematic Review and Pooled Analysis. Eur Urol 2018; 74(5):611-620.
8. Spek A, Szabados B, Casuscelli J, et al. Adjuvant therapy in renal cell carcinoma: the perspective of urologists. Int J Clin Oncol 2019; 24(6):694-697.
9. Martinez Chanza N, Tripathi A, Harshman LC. Adjuvant Therapy Options in Renal Cell Carcinoma: Where Do We Stand? Curr Treat Options Oncol 2019; 20(5):44.
10. Gleeson JP, Motzer RJ, Lee CH. The current role for adjuvant and neoadjuvant therapy in renal cell cancer. Curr Opin Urol 2019.
11. Ljungberg B, Albiges L, Abu-Ghanem Y, et al. European Association of Urology Guidelines on Renal Cell Carcinoma: The 2019 Update. Eur Urol 2019; 75(5):799-810.
12. Wood C, Srivastava P, Bukowski R, et al. An adjuvant autologous therapeutic vaccine (HSPPC-96; vitespen) versus observation alone for patients at high risk of recurrence after nephrectomy for renal cell carcinoma: a multicentre, open-label, randomised phase III trial. Lancet 2008; 372(9633):145-54.
13. Aitchison M, Bray CA, Van Poppel H, et al. Final results from an EORTC (GU Group)/NCRI randomized phase III trial of adjuvant interleukin-2, interferon alpha, and 5-fluorouracil in patients with a high risk of relapse after nephrectomy for renal cell carcinoma (RCC). Journal of Clinical Oncology 2011; 29(15 (SUPPL)):4505.
14. Tsimafeyeu ID, L., Kharkevich G, Petenko N, et al. Granulocyte-Macrophage Colony-Stimulating Factor, Interferon Alpha and Interleukin-2 as Adjuvant Treatment for High-Risk Renal Cell Carcinoma. J Cancer Sci Ther 2010; 2:157-159.
15. Motzer RJ, Tannir NM, McDermott DF, et al. Nivolumab plus Ipilimumab versus Sunitinib in Advanced Renal-Cell Carcinoma. N Engl J Med 2018; 378(14):1277-1290.
16. Motzer RJ, Penkov K, Haanen J, et al. Avelumab plus Axitinib versus Sunitinib for Advanced Renal-Cell Carcinoma. N Engl J Med 2019; 380(12):1103-1115.
17. Rini BI, Plimack ER, Stus V, et al. Pembrolizumab plus Axitinib versus Sunitinib for Advanced Renal-Cell Carcinoma. N Engl J Med 2019; 380(12):1116-1127.

The Current Status of Cytoreductive Nephrectomy

Kidney cancer is the 6th most common malignancy among men and 10th most among women.1 Renal cell carcinoma (RCC) accounts for the vast majority of these tumors. Further details regarding the epidemiology of kidney cancer have been discussed in, "Epidemiology and Etiology of Kidney Cancer." While 20-30% of patients undergoing nephrectomy will develop metastases during follow-up,2 a significant proportion (historically up to 25-30%) of patients with renal cell carcinoma present with metastases at the time of diagnosis.3 More recent estimates suggest that, with stage migration due to an increasing incidental diagnosis of kidney cancer, approximately 15% of patients newly diagnosed with kidney cancer have metastases at the time of diagnosis.1 Historically, patients treated with cytokine-based systemic therapy had a median overall survival of 10 months.3 Therefore, options to improve outcomes for these patients were sought.

The History of Cytoreductive Nephrectomy

The notion of cytoreductive nephrectomy (CN), removal of the kidney and primary tumor in the face of metastatic disease, was based on a series of observations. First, patients treated with the primary tumor in-situ who underwent treatment with interferon fared particularly poorly.2,4 Second, case reports demonstrated that a small number of patients treated with CN experienced regression of their metastatic disease.5,6

As a result, two randomized controlled trials were undertaken to assess the value of CN in the era of cytokine-based therapy. In these two methodologically similar randomized controlled trials, Flanigan et al. and Mickish et al. randomized patients to CN plus interferon vs interferon alone.7 Reported in 2001, among 241 American patients, Flanigan et al. demonstrated a 3-month survival benefit8 whereas, among 83 European participants, Mickish et al. demonstrated a 10-month survival benefit.9 Subsequent pooled analyses showed a strongly statistically significant benefit with overall survival of 13.6 months among patients receiving CN plus interferon and 7.8 months among those receiving interferon alone (difference = 5.8 months, p=0.002).7 On the basis of these data, CN became part of the treatment paradigm for metastatic RCC.

It bears mention that despite the proven survival benefits, the mechanism of CN is unclear. Notably, the response to systemic therapy did not differ in the two pivotal RCTs.7 thus, CN does not potentiate the response to (cytokine-based) systemic therapy. Postulated mechanisms include removal of the “immunologic sink”,4,10 decreased production of cytokines and growth factors by the primary tumor,11-13 delayed metastatic progression,14 and survival benefit from nephrectomy induced azotemia.15

However, shortly after the publication of the randomized data demonstrating the survival benefit to adding cytoreductive nephrectomy to cytokine-based systemic therapy, the introduction of targeted therapies revolutionized the systemic therapy of metastatic RCC. From the aforementioned 10-month median overall survival in the cytokine-era,3 median overall survival for patients receiving a sequential regime of targeted therapies may exceed 40 months.16 Much more detail regarding systemic therapy in advanced RCC is available in the article, "Systemic Therapy for Advanced Renal Cell Carcinoma."

Cytoreductive Nephrectomy in the Targeted Therapy Era

A number of retrospective studies have examined the role of cytoreductive nephrectomy in the context of targeted therapy. Summarized by Bhindi et al. in a recent systematic review,17 these 10 retrospective studies consistently demonstrated a significant survival benefit to cytoreduction. However, the potential for selection bias is significant among these studies, particularly among studies in which it was not possible to quantify the burden of metastatic disease.

The CARMENA trial (Cancer du Rein Metastatique Nephrectomie et Antiangiogéniques or, alternatively, Clinical Trial to Assess the Importance of Nephrectomy) provides the only available randomized data on the role of cytoreductive nephrectomy in the targeted therapy era.18 This study has been extensively reported on by UroToday authors including “ASCO 2018: Sunitinib Alone Shows Non-inferiority Versus Standard of Care in mRCC - The CARMENA Study," “ASCO 2018: CARMENA: Cytoreductive Nephrectomy Followed by Sunitinib vs. Sunitinib Alone in Metastatic Renal Cell Carcinoma - Results of a Phase III Noninferiority Trial," and “Nephrectomy in the Era of Targeted Therapy: Takeaways from the CARMENA Trial."

To briefly summarize, CARMENA randomized 450 patients with intermediate or poor-risk confirmed clear cell renal cell carcinoma in a 1:1 fashion to nephrectomy followed by sunitinib or sunitinib alone.18 To be eligible for enrollment in CARMENA, patients had to be naïve to systemic therapy, eligible for treatment with sunitinib and deemed amenable for cytoreductive nephrectomy by their treating surgeon. Using the Memorial Sloan Kettering Cancer Center (MSKCC) risk stratification, these patients had intermediate- or poor-risk disease. Additionally, patients had to have an ECOG performance score of 0 or 1 and no evidence of brain metastasis or have undergone prior local therapy for brain metastasis without evidence of progression for at least 6 weeks. After a median follow-up of 51 months, the median overall survival for patients receiving systemic therapy alone was 18.4 months and was 13.9 months for those patients undergoing cytoreductive nephrectomy followed by sunitinib. The resulting Cox models demonstrated non-inferiority with a hazard ratio of 0.89 (95% CH 0.71 to 1.10) based on an intention to treat analysis. In a per-protocol analysis, the resultant analysis showed comparable results (HR 0.98, 95% CI 0.77 to 1.25). However, in this case, the upper limit of the 95% confidence interval crossed the investigator's pre-specified non-inferiority threshold of 1.20.

A number of nuances regarding CARMENA bear consideration. First, the investigators required eight years at 79 sites to accrue 450 of an initially planned 576 patients. Thus, each institution enrolled fewer than a single patient each year – suggesting either that many potentially eligible patients may not have been enrolled due to either their clinician’s lack of equipoise (and thus unwillingness to leave treatment allocation to chance) or the patients’ own unwillingness to be randomized. The resulting cohort, while having a good performance status (ECOG 0 or 1) and deemed fit for cytoreductive nephrectomy, the enrolled patients had a significantly higher burden of disease that may be expected from population-based American cohorts.19 Second, there was significant cross-over within the study, with a large proportion of patients assigned to sunitinib alone eventually undergoing palliative nephrectomy for symptomatic control. Potentially more concerning, given the proven survival benefit of targeted therapy, are the patients who were not able to receive sunitinib following cytoreductive nephrectomy.

To further address the question of the timing of cytoreductive nephrectomy, the SURTIME trial (Immediate Surgery or Surgery after Sunitinib Malate In Treating Patients with Kidney Cancer (NCT01099423) randomized 99 patients to immediate CN followed by sunitinib, beginning 4 weeks after surgery and continuing for four courses, or three 6-week courses of sunitinib (in the absence of disease progression or unacceptable toxicity) followed by CN followed by 2 courses of adjuvant sunitinib. While significantly underpowered due to poor accrual, the trial reported a 28-week progression-free rate of 42% in the immediate CN arm and 43% in the deferred CN arm (p=0.6).20 Interestingly, intention-to-treat analysis of the secondary outcome of overall survival demonstrated significantly longer survival among patients in the delayed CN arm (median 32.4 months) compared to the immediate CN arm (median 15.1 months) (HR 0.57, 95% CI 0.34 to 0.95).

Since these trials were designed and accrued, a number of additional systemic therapy agents have been approved for first-line therapy in metastatic RCC. Many of these agents have demonstrated superiority to sunitinib.21 While improved overall survival increases the time for patients to develop local symptoms which may warrant surgery, improved systemic therapy is likely to reduce the value of local treatments. Notably, the efficacy of nivolumab and ipilimumab did not differ on the basis of whether the patient had previously undergoing nephrectomy.22

Taken together, CARMENA and SURTIME suggest that systemic therapy should be prioritized over cytoreductive nephrectomy for patients with metastatic RCC. However, the EAU guidelines, while emphasizing the CN is no longer the standard of care, highlight that CN may be considered for select patients including those with an intermediate-risk disease who have a long-term sustained benefit from systemic therapy and those with a good-risk disease who do not require systemic therapy.23

Published Date: April 16th, 2019
Written by: Christopher J.D. Wallis, MD, PhD and Zachary Klaassen, MD, MSc
References:
  1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2018. CA: a cancer journal for clinicians. 2018;68(1):7-30.
  2. Ljungberg B, Campbell SC, Choi HY, et al. The epidemiology of renal cell carcinoma. European Urology. 2011;60(4):615-621.
  3. Motzer RJ, Mazumdar M, Bacik J, Berg W, Amsterdam A, Ferrara J. Survival and prognostic stratification of 670 patients with advanced renal cell carcinoma. Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 1999;17(8):2530-2540.
  4. Robertson CN, Linehan WM, Pass HI, et al. Preparative cytoreductive surgery in patients with metastatic renal cell carcinoma treated with adoptive immunotherapy with interleukin-2 or interleukin-2 plus lymphokine activated killer cells. The Journal of urology. 1990;144(3):614-617; discussion 617-618.
  5. Marcus SG, Choyke PL, Reiter R, et al. Regression of metastatic renal cell carcinoma after cytoreductive nephrectomy. The Journal of urology. 1993;150(2 Pt 1):463-466.
  6. Snow RM, Schellhammer PF. Spontaneous regression of metastatic renal cell carcinoma. Urology. 1982;20(2):177-181.
  7. Flanigan RC, Mickisch G, Sylvester R, Tangen C, Van Poppel H, Crawford ED. Cytoreductive nephrectomy in patients with metastatic renal cancer: a combined analysis. The Journal of urology. 2004;171(3):1071-1076.
  8. Flanigan RC, Salmon SE, Blumenstein BA, et al. Nephrectomy followed by interferon alfa-2b compared with interferon alfa-2b alone for metastatic renal-cell cancer. The New England journal of medicine. 2001;345(23):1655-1659.
  9. Mickisch GH, Garin A, van Poppel H, et al. Radical nephrectomy plus interferon-alfa-based immunotherapy compared with interferon alfa alone in metastatic renal-cell carcinoma: a randomised trial. Lancet. 2001;358(9286):966-970.
  10. Spencer WF, Linehan WM, Walther MM, et al. Immunotherapy with interleukin-2 and alpha-interferon in patients with metastatic renal cell cancer with in situ primary cancers: a pilot study. The Journal of urology. 1992;147(1):24-30.
  11. Lahn M, Fisch P, Kohler G, et al. Pro-inflammatory and T cell inhibitory cytokines are secreted at high levels in tumor cell cultures of human renal cell carcinoma. European urology. 1999;35(1):70-80.
  12. Kawata N, Yagasaki H, Yuge H, et al. Histopathologic analysis of angiogenic factors in localized renal cell carcinoma: the influence of neoadjuvant treatment. Int J Urol. 2001;8(6):275-281.
  13. Slaton JW, Inoue K, Perrotte P, et al. Expression levels of genes that regulate metastasis and angiogenesis correlate with advanced pathological stage of renal cell carcinoma. Am J Pathol. 2001;158(2):735-743.
  14. Lara PN, Jr., Tangen CM, Conlon SJ, Flanigan RC, Crawford ED, Southwest Oncology Group Trial S. Predictors of survival of advanced renal cell carcinoma: long-term results from Southwest Oncology Group Trial S8949. The Journal of urology. 2009;181(2):512-516; discussion 516-517.
  15. Gatenby RA, Gawlinski ET, Tangen CM, Flanigan RC, Crawford ED. The possible role of postoperative azotemia in enhanced survival of patients with metastatic renal cancer after cytoreductive nephrectomy. Cancer research. 2002;62(18):5218-5222.
  16. Escudier B, Goupil MG, Massard C, Fizazi K. Sequential therapy in renal cell carcinoma. Cancer. 2009;115(10 Suppl):2321-2326.
  17. Bhindi B, Abel EJ, Albiges L, et al. Systematic Review of the Role of Cytoreductive Nephrectomy in the Targeted Therapy Era and Beyond: An Individualized Approach to Metastatic Renal Cell Carcinoma. European Urology. 2019;75(1):111-128.
  18. Mejean A, Ravaud A, Thezenas S, et al. Sunitinib Alone or after Nephrectomy in Metastatic Renal-Cell Carcinoma. The New England journal of medicine. 2018.
  19. Arora S, Sood A, Dalela D, et al. Cytoreductive Nephrectomy: Assessing the Generalizability of the CARMENA Trial to Real-world National Cancer Data Base Cases. European urology. 2019;75(2):352-353.
  20. Bex A, Mulders P, Jewett M, et al. Comparison of Immediate vs Deferred Cytoreductive Nephrectomy in Patients with Synchronous Metastatic Renal Cell Carcinoma Receiving Sunitinib: The SURTIME Randomized Clinical Trial. JAMA Oncol. 2018.
  21. Wallis CJD, Klaassen Z, Bhindi B, et al. First-line Systemic Therapy for Metastatic Renal Cell Carcinoma: A Systematic Review and Network Meta-analysis. European urology. 2018;74(3):309-321.
  22. Motzer RJ, Tannir NM, McDermott DF, et al. Nivolumab plus Ipilimumab versus Sunitinib in Advanced Renal-Cell Carcinoma. The New England journal of medicine. 2018;378(14):1277-1290.
  23. Bex A, Albiges L, Ljungberg B, et al. Updated European Association of Urology Guidelines for Cytoreductive Nephrectomy in Patients with Synchronous Metastatic Clear-cell Renal Cell Carcinoma. European Urology. 2018;74(6):805-809.

Radiopharmaceuticals in Prostate Cancer: Systemic “Bone-Seeking” Agents

Radiopharmaceuticals are pharmaceutical agents containing radioisotopes and emitting radiation that may be used for diagnostic or treatment purposes.

A number of small molecules have been used in conjunction with positron emission tomography (PET) scanning for prostate cancer staging. A recent presentation reported on the role of radiopharmaceutical driven imaging, predominately using Ga-PSMA, from the 2018 American Society of Clinical Oncology Annual Meeting.

From a therapeutic perspective, as they are typically given via intravenous infusion, radiopharmaceuticals are systemic radiotherapies, emitting alpha or beta radiation. Radiopharmaceuticals are indicated in patients with castrate-resistant prostate cancer with symptomatic bone metastases. Historically, beta-particle emitting agents including strontium-89 (Metastron®), samarium-153 (Quadramet®), phosphorus-32, and rhenium-186 were used as palliative therapies for patients with symptomatic bone disease.1 In this context, they are quite effective in relieving bony pain,2 however, these agents did not significantly improve survival.3 In contrast, the ALSYMPCA trial, which will be discussed in more detail below, demonstrated an improvement in both overall survival and skeletal-related events for patients receiving the alpha-emitter radium-223.4

In December 2018, the European Association of Nuclear Medicine Focus 1 Meeting reported a consensus regarding the use of molecular imaging and theranostics in prostate cancer.5 A number of relevant conclusions were derived following a systematic review and modified Delphi process. First, traditional diphosphate bone scan and contrast-enhanced computed tomography scan are mentioned but rarely recommended in the majority of patients in clinical guidelines. Second, magnetic resonance imaging and prostate cancer-targeted positron emission tomography are frequently suggested but the specific clinical scenarios in which they are most useful are poorly defined and how they may affect practice are poorly delineated. Third, sodium fluoride-18 positron emission tomography-CT bone scanning is not widely recommended; however, gallium-68 or fluorine-18 PSMA have gained acceptance. Finally, the palliative use of bone-targeting radiopharmaceuticals strontium-89, samarium-153, and rhenium-186 has been supplanted by radium-223, as well as other systemic therapies including docetaxel, abiraterone acetate, enzalutamide, and cabazitaxel.

Radium-223

Radium-223 dichloride (Xofigo®), commonly referred to as radium-223, is a targeted alpha emitter. It functions as a calcium mimetic and selectively binds newly forming bone stroma in regions of high bone turnover in osteoblastic or sclerotic bone metastasis.6 It then emits high-energy alpha particles with a very short range (less than 100 μm).7 This high-energy radiation induces a highly localized cytotoxic effect due to double-stranded DNA breakage.

Initial Phase I and Phase II studies in patients with bone metastasis demonstrated radium-223 to be well tolerated, with minimal myelosuppression.8,9 Phase II trials also demonstrated that radium-223 effectively reduced bone-related pain and improved disease-related biomarkers, including bone alkaline phosphatase and prostate-specific antigen (PSA).9

As a result, the Phase III, Alpharadin in Symptomatic Prostate Cancer Patients (ALSYMPCA) trial was undertaken to assess the efficacy of radium-223 versus placebo in patients with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases across 136 study centers in 19 countries.4 The trial enrolled patients with two or more bone metastases, detected on skeletal scintigraphy, without visceral metastasis who had previously received docetaxel, were docetaxel ineligible or declined docetaxel. Patients were required to have symptomatic disease, based on the requirement for regular analgesics or prior treatment with external beam radiotherapy for cancer-related bone pain in the preceding 12 weeks. Additionally, patients had to have a baseline PSA of at least 5 ng/mL with at least two progressive PSA rises; an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2; life expectancy of at least six months; and adequate hematologic, renal and liver function. Patients who had received chemotherapy within the preceding four weeks were excluded.

A total of 921 patients were enrolled and were randomized in a 2:1 ratio to radium-223 (50 kBq per kilogram of body weight intravenously), once every four weeks, plus best standard of care or placebo plus best standard of care.

The primary study endpoint was overall survival and secondary outcomes included time to first symptomatic skeletal event; biochemical endpoints including time to increase in total alkaline phosphatase level, total alkaline phosphatase response, normalization of alkaline phosphatase, time to increase in PSA; safety endpoints; and quality of life.

An initial, pre-specified, interim analysis was undertaken when 314 deaths had occurred. This demonstrated longer median overall survival among patients who received radium-223 (14.0 months) than those receiving placebo (11.2 months) with a resulting 30% decrease in the risk of death (hazard ratio 0.70, 95% 0.55 to 0.88). A subsequent, updated analysis was performed following 528 deaths. This demonstrated consistent results with longer median overall survival among patients who received radium-223 (14.9 months) than those receiving placebo (11.3 months). Similarly, the updated analysis confirmed a 30% reduction in the risk of death (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.58 to 0.83) for patients receiving radium-223. This benefit was observed across subgroups including total alkaline phosphatase level at randomization, current bisphosphonate use, previous docetaxel treatment, baseline ECOG score (0/1 vs 2), extent of disease (<6 metastases, 6-20 metastases, >20 metastases, and super scan), and opioid use.

Assessment of the secondary endpoints demonstrated a consistent benefit for radium-223. Notably, radium-223 delayed time to first symptomatic skeletal event (median, 15.6 months vs 9.8 months; HR 0.66, 95% CI 0.52 to 0.83). Unlike many systemic therapies, patients who received radium-223 were less likely to experience adverse events than those who received placebo: all adverse events (93% vs 96%), grade 3 or 4 adverse events (56% vs 62%), serious adverse events (47% vs 60%), and treatment-discontinuation as a result of adverse events (16% vs 21%). Finally, patients who received radium-223 were significantly more likely to have an improvement in the quality of life compared to patients receiving a placebo (p=0.02).

The authors subsequently published a pre-planned analysis with stratification according to receipt of prior docetaxel.10 Radium-223 prolonged survival both in patients who had previously received docetaxel (HR 0.70, 95% CI 0.56 to 0.88) and those who had not previously received docetaxel (HR 0.69 (95% CI 0.52 to 0.92).

As both radium-223 and abiraterone acetate11,12 have demonstrated survival benefits in patients with metastatic castrate-resistant prostate cancer, there was interest in combining these two agents. The ERA 223 trial randomized 806 patients with chemotherapy-naïve, metastatic castrate-resistant prostate cancer with bone metastasis to radium-223 or placebo, in addition to abiraterone acetate. Symptomatic skeletal event-free survival was the primary outcome. Somewhat unexpectedly, the trial was unblinded prematurely as more fractures and deaths were identified in the radium-223 arm than among patients receiving placebo. Median skeletal event-free survival was 22.3 months (interquartile range 17.0 to 25.8 months) among patients receiving radium-223 and abiraterone acetate and 26.0 months (interquartile range 21.8 months to 28.3 months) in patients receiving placebo and abiraterone acetate (HR 1.12, 95% CI 0.92 to 1.37). Fractures were more common among patients receiving radium-223 and abiraterone acetate (29%) than those receiving placebo and abiraterone acetate (11%). Thus, the combination of radium-223 and abiraterone acetate is not recommended in combination, however other combinations of agents with radium-223 are currently being tested (ie. enzalutamide).

Role of Radiopharmaceuticals in the AUA Guideline

The American Urological Association Guideline on Castrate-Resistant Prostate Cancer (amended in 2018) defines a number of clinical scenarios in which radiopharmaceuticals may be considered.13

First, among patients with good performance status and have not yet received docetaxel but who are symptomatic (based on a definition requiring regular use of narcotic analgesics for pain that is attributable to documented metastasis), radium-223 may be offered to patients who have symptoms attributable to bony metastatic disease in the absence of visceral disease in addition to standard of care options including abiraterone acetate plus prednisone, enzalutamide, and docetaxel. Patients with symptomatic metastases who decline these standard therapies, alternative treatments including radionuclide therapy (such as strontium-89) may be offered.13

Second, for symptomatic patients with poor performance status who have not previously received docetaxel, there is a relative paucity of direct evidence to inform treatment choices as most patients with poor performance status are excluded from clinical trials. Based on extrapolation from studies in patients with better performance status, the guideline recommends considering aggressive prostate cancer treatment where the functional impairments resulting in poor performance status are directly attributable to prostate cancer. In cases where the poor performance status is related to bony metastatic disease, radium-223 is a recommended option.13

Third, among patients with metastatic castrate-resistant prostate cancer who have previously received docetaxel-based chemotherapy, radium-223 is one of four agents with a proven survival benefit, along with abiraterone acetate plus prednisone, enzalutamide, and cabazitaxel.

Fourth, and finally, in patients with advanced mCRPC who are symptomatic and have poor performance status following previous docetaxel chemotherapy, symptom management is strongly advocated in keeping with the American Society for Clinical Oncology’s guidance regarding the treatment of patients with advanced solid tumors. However, judicious use of radionuclide therapy, along with abiraterone acetate plus prednisone, enzalutamide, ketoconazole plus steroids, are offered within the AUA guidelines13 despite the lack of strong data to support the use of these agents in this patient population.

The Canadian Urologic Association Guidelines similarly recommend radium-223 in patients with metastatic castrate-resistant prostate cancer who have bone pain related to their metastases and no visceral disease.14

New directions

The ALSYMPCA trial was the first to demonstrate that radiopharmaceuticals could improve overall survival, in addition to skeletal-related events,4 in patients with metastatic castrate-resistant prostate cancer. On the basis of this observation, there is an ongoing effort to identify molecular targets for linkage to radiopharmaceuticals. Proposed targets have included prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptors (GRPr),15 These have the advantage of targeting prostate cancer cells, rather than being inherently bone targeting as is the case for current radiopharmaceuticals. Thus far, preliminary data based on prostate-specific membrane antigen targeted beta-emitters such as lutetium-177 suggest a promise to this approach but further work remains prior to the adoption of this approach.1 Further, ongoing research assessing prostate-specific membrane antigen targeted alpha-emitters is ongoing.

Written by: Zachary Klaassen, MD, MSc, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, Atlanta, Georgia

Published Date: December 2019

Written by: Christopher J.D. Wallis, MD, PhD and Zachary Klaassen, MD, MSc
References:

1. Sartor, Oliver. "Isotope therapy for castrate-resistant prostate cancer: unique sequencing and combinations." The Cancer Journal 22, no. 5 (2016): 342-346.
2. Ye, Xiaojuan, Da Sun, and Cen Lou. "Comparison of the efficacy of strontium-89 chloride in treating bone metastasis of lung, breast, and prostate cancers." Journal of cancer research and therapeutics 14, no. 8 (2018): 36.
3. James, Nicholas, Sarah Pirrie, Ann Pope, Darren Barton, Lazaros Andronis, Ilias Goranitis, Stuart Collins et al. "TRAPEZE: a randomised controlled trial of the clinical effectiveness and cost-effectiveness of chemotherapy with zoledronic acid, strontium-89, or both, in men with bony metastatic castration-refractory prostate cancer." Health Technology Assessment 20 (2016).
4. Parker, Christopher, S. Nilsson, Daniel Heinrich, Svein I. Helle, J. M. O'sullivan, Sophie D. Fosså, Aleš Chodacki et al. "Alpha emitter radium-223 and survival in metastatic prostate cancer." New England Journal of Medicine 369, no. 3 (2013): 213-223.
5. Fanti, Stefano, Silvia Minozzi, Gerald Antoch, Ian Banks, Alberto Briganti, Ignasi Carrio, Arturo Chiti et al. "Consensus on molecular imaging and theranostics in prostate cancer." The Lancet Oncology 19, no. 12 (2018): e696-e708.
6. Henriksen, Gjermund, Knut Breistøl, Øyvind S. Bruland, Øystein Fodstad, and Roy H. Larsen. "Significant antitumor effect from bone-seeking, α-particle-emitting 223Ra demonstrated in an experimental skeletal metastases model." Cancer research 62, no. 11 (2002): 3120-3125.
7. Bruland, Øyvind S., Sten Nilsson, Darrell R. Fisher, and Roy H. Larsen. "High-linear energy transfer irradiation targeted to skeletal metastases by the α-emitter 223Ra: adjuvant or alternative to conventional modalities?." Clinical cancer research 12, no. 20 (2006): 6250s-6257s.
8. Nilsson, Sten, Roy H. Larsen, Sophie D. Fosså, Lise Balteskard, Kari W. Borch, Jan-Erik Westlin, Gro Salberg, and Øyvind S. Bruland. "First clinical experience with α-emitting radium-223 in the treatment of skeletal metastases." Clinical cancer research 11, no. 12 (2005): 4451-4459.
9. Nilsson, Sten, Lars Franzén, Christopher Parker, Christopher Tyrrell, René Blom, Jan Tennvall, Bo Lennernäs et al. "Bone-targeted radium-223 in symptomatic, hormone-refractory prostate cancer: a randomised, multicentre, placebo-controlled phase II study." The lancet oncology 8, no. 7 (2007): 587-594.
10. Hoskin, Peter, Oliver Sartor, Joe M. O'Sullivan, Dag Clement Johannessen, Svein I. Helle, John Logue, David Bottomley et al. "Efficacy and safety of radium-223 dichloride in patients with castration-resistant prostate cancer and symptomatic bone metastases, with or without previous docetaxel use: a prespecified subgroup analysis from the randomised, double-blind, phase 3 ALSYMPCA trial." The Lancet Oncology 15, no. 12 (2014): 1397-1406.
11. Ryan, Charles J., Matthew R. Smith, Johann S. De Bono, Arturo Molina, Christopher J. Logothetis, Paul De Souza, Karim Fizazi et al. "Abiraterone in metastatic prostate cancer without previous chemotherapy." New England Journal of Medicine 368, no. 2 (2013): 138-148.
12. De Bono, Johann S., Christopher J. Logothetis, Arturo Molina, Karim Fizazi, Scott North, Luis Chu, Kim N. Chi et al. "Abiraterone and increased survival in metastatic prostate cancer." New England Journal of Medicine 364, no. 21 (2011): 1995-2005.
13. Lowrance, William T., Mohammad Hassan Murad, William K. Oh, David F. Jarrard, Matthew J. Resnick, and Michael S. Cookson. "Castration-resistant prostate cancer: AUA Guideline Amendment 2018." The Journal of urology 200, no. 6 (2018): 1264-1272.
14. Saad, Fred, Kim N. Chi, Antonio Finelli, Sebastien J. Hotte, Jonathan Izawa, Anil Kapoor, Wassim Kassouf et al. "The 2015 CUA-CUOG Guidelines for the management of castration-resistant prostate cancer (CRPC)." Canadian Urological Association Journal 9, no. 3-4 (2015): 90.
15. Maffioli, L., L. Florimonte, D. Costa, C. Correia, C. Grana, M. Luster, L. Bodei, and M. Chinol. "New radiopharmaceutical agents for the treatment of castration-resistant prostate cancer." Quart J Nuclear Med Molec Imaging 59 (2015): 420-438.

Prostate Cancer and Utilization of Multi-Parametric MRI

Over the last decade, imaging for prostate cancer has improved immensely. Specifically, prostate multiparametric MRI (mpMRI) has improved primarily as a result of an increase in magnet strength from 1 to 3-tesla. mpMRI consists of anatomic and functional imaging techniques: anatomic imaging includes T1- and T2-weighted images, and functional imaging includes diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) sequences. Currently, the recommendation is for a 1.5 tesla MRI with an endorectal coil or a 3-tesla MRI with no endorectal coil.1 

Initial T1-weighted images are performed first to determine if hemorrhage is present in the prostate. As such, most experts recommend waiting 3-8 weeks after a prostate biopsy to decrease artifact associated with hemorrhage from the biopsy.2 Subsequently, T2-weighted images provide anatomic configuration of the prostate gland: the normal peripheral zone appears as areas of high signal intensity, whereas areas of low signal intensity may represent prostate cancer, prostatitis, BPH, etc. T2-weighted images also provide information regarding extraprostatic extension (EPE) or seminal vesical invasion (SVI), which are represented by areas of low signal intensity. DWI assess the diffusion of water within the magnetic field—the closer the cells are together (ie. for a prostate cancer nodule), the lower the motion of water, which leads to a high signal intensity in this phase. The DCE phase is a T1-weighed image with gadolinium-based contrast, which assesses vascular permeability of the prostate over a period of typically 5-10 minutes. Importantly, the combination of T2, DCE, and DWI phases yields both a NPV and PPV of >90%.3


table-1-prostate-cancer-utilization@2x.jpg


The objective of this article is to focus on indications for mpMRI use in the localized prostate cancer setting, specifically exploring its use before prostate biopsy, after a negative biopsy, on active surveillance, and prior to radical prostatectomy for surgical planning purposes.

Before Prostate Biopsy

Until recently, the utilization of mpMRI as a “triage test” prior to transrectal ultrasound (TRUS)-guided prostate biopsy was a contentious topic, relying on single centers suggesting that such an approach may decrease unnecessary biopsies.5,6 However, in 2017, the PROMIS trial provided level 1b evidence for utilizing mpMRI prior to TRUS-guided biopsy among men with elevated PSA.7 PROMIS was a multi-center, paired-cohort study to assess the diagnostic accuracy of mpMRI and TRUS biopsy against a gold-standard reference template mapping biopsy. Men were included (n=576) if they had a PSA <15 ng/ml and no history of the previous biopsy. On mapping biopsy, 71% of men had cancer, including 40% with clinically significant prostate cancer (Gleason score ≥4+3 or maximum cancer length ≥6 mm). For clinically significant disease, mpMRI was more sensitive (93%) than TRUS-biopsy (48%), albeit less specific (41% for mpMRI; 96% for TRUS-biopsy). Based on these data, a triage mpMRI would allow 25% of men to safely avoid a prostate biopsy, while at the same time reducing detection of clinically insignificant prostate cancer. Importantly, secondary to the poor specificity and positive predictive value, this study does not suggest that mpMRI should replace prostate biopsy and that men with suspicious lesions should still have histologic confirmation of prostate cancer.

Shortly after PROMIS was published, PRECISION reported results of their trial which assigned 500 men with a clinical suspicion of prostate cancer who had not previously undergone a prostate biopsy to undergo MRI with or without a targeted biopsy vs standard TRUS-guided biopsy.8 Men in the MRI group underwent a targeted biopsy if there was a suspicion of prostate cancer on imaging and did not undergo a biopsy if the MRI was negative. The primary outcome for this randomized clinical trial was a diagnosis of clinically significant prostate cancer. In the MRI-targeted biopsy group, 28% had a negative MRI and thus no biopsy. Among men undergoing targeted biopsy, 38% had clinically significant cancer, compared to 26% in the TRUS-guided biopsy group (p=0.005). Furthermore, fewer men in the MRI-targeted biopsy group had clinically insignificant prostate cancer compared to the TRUS-guided biopsy group.

Since the publication of these two trials, debate regarding the implementation of mpMRI prior to biopsy has ensued. Detractors have mentioned that the negative predictive value of mpMRI in PROMIS for detecting Gleason grade group ≥2 was only 76%, albeit no grade group ≥3 were missed on mpMRI.7 mpMRI prior to prostate biopsy has already been widely accepted in the UK and Australia where mpMRI is reimbursed in this setting.9 There is evidence to suggest that men with a negative mpMRI should not be biopsied unless caveats such as a strong family history, abnormal digital rectal exam, or BRCA mutation are present. At present, experts have pressed for a new paradigm for prostate cancer detection in which an abnormal mpMRI should have a targeted biopsy performed; if the mpMRI is negative then a routine follow-up protocol should be employed.9 It is noteworthy to mention that widespread dissemination will undoubtedly rely on (i) affordability/reimbursement of mpMRI, (ii) quality of the mpMRI, and (iii) skill of the radiologist.

After Negative Prostate Biopsy

It is generally accepted that men with a history of negative TRUS-guided biopsy and persistently elevated or increasing PSA should undergo a mpMRI prior to consideration of a second (or in some cases third or fourth) prostate biopsy. In a study of 265 patients with a PSA >4.0 ng/ml and one negative TRUS-biopsy mpMRI detected prostate cancer in 41% of men, including 87% with clinically significant prostate cancer.10 

mpMRI has been shown in the previous negative biopsy setting to detect tumors in up to 40% of cases, often in the anterior region of the prostate.11-14 An advantage of mpMRI fusion biopsy in patients with prior negative biopsy is the ability of MRI to identify suspicious lesions in areas not normally sampled by standard TRUS-guided biopsy, specifically the anterior and apical parts of the prostate. Thus, the benefit of fusion biopsy is particularly accentuated in the prior negative biopsy cohort. Furthermore, a study by Kongnyuy et al.15 suggested that there may be racial differences with regards to anterior tumors. In a cohort of 195 African-American men matched 1:1 to white men undergoing mpMRI, 47.7% of African-American men had anterior prostate lesions. Amongst these men, a history of prior negative biopsy was significantly associated with an anterior prostate lesion (OR 1.81, 95%CI 1.03-3.20). Despite an overall higher cancer detection rate among African American than white men, the presence of anterior prostate lesions and lesions harboring clinically significant cancer were not different between races.

On Active Surveillance

Over the last decade, adoption of active surveillance as a management strategy for men with clinically low-risk prostate cancer has appropriately continued to increase. However, until recently, the utilization of mpMRI in active surveillance management has been somewhat discretionary and clinician dependent.16

Earlier this year the European Association of Urology (EAU) released a position statement for active surveillance, which included 10 recommendation statements;17 the 3rd statement assessed “use and timing of MRI in active surveillance.” mpMRI can be used to increase clinically significant cancer detection, thus ensuring men are appropriately included in surveillance regimens and those with potentially threatening disease can have appropriate and timely intervention. The statement recommends that mpMRI can be performed at several time points during active surveillance:

  1. At the time of initial diagnosis – the EAU statement recommends that men diagnosed with a low-risk disease without a prior mpMRI should under a mpMRI prior to enrolment to ensure no significant disease was missed on initial biopsy. In cases of initial targeted mpMRI biopsy, both targeted and systematic biopsies should be performed.17 In addition to the excitement generated by PROMIS 7 and PRECISION,8 a recent systematic review assessed the role of mpMRI among active surveillance patients, noting that a lesion suspicious for prostate cancer was found in nearly two-thirds of men otherwise suitable for surveillance.18
  2. Before confirmatory biopsy – the EAU statement recommends that a mpMRI be performed before the confirmatory biopsy, within 12 months from initial diagnosis, and to include targeted and systematic biopsies.17 The rate of reclassification after targeted biopsies among men on active surveillance without a prior mpMRI may be as high as 22%.18-20 A recent publication assessed the value of serial mpMRI imaging among 111 men on active surveillance with > 1-year of follow-up, noting that among 33 reclassifications after one year, 55% were reclassified on only TRUS-guided biopsy.21 As such, the value of serial mpMRI in active surveillance algorithms remains unclear.
  3. During follow-up – the EAU statement does not support the use of solely using mpMRI instead of repeat biopsy in active surveillance follow-up.17 As mentioned, the use of serial mpMRIs over long-term follow-up is not currently recommended, however it may be used in situations where a targeted lesion is being followed. This is an area of great research interest considering that institutional studies with vast experience with mpMRI suggest that mpMRI supplanting follow-up biopsies is safe and feasible.22  
Last month, the ASIST trial published results of the randomized, multicenter, prospective trial assessing if mpMRI with targeted biopsy could identify a greater proportion of men with grade group ≥2 cancer on confirmatory biopsy compared with systematic biopsies.23 Among 273 men included in the study, 64% in the MRI group had a suspicious region of interest. Unfortunately, no difference was observed in the rate of grade group ≥2 upgrading in the intention to treat or per protocol cohort, grade group ≥2 upgrading within each stratum separately, or grade group ≥3. This trial confirms that there is still a role for TRUS-guided biopsy among active surveillance patients, in addition to tempering the current role for targeted biopsies in this setting.

Before Radical Prostatectomy

With improved mpMRI technology has come an interest in more precise clinical staging of localized prostate cancer, particularly before performing radical prostatectomy. Ultimately, the patient and urologist are concerned about the risk of EPE preoperatively, which dictates the degree of nerve-sparing performed at the time of radical prostatectomy. Somford et al.24 assessed mpMRI images among 183 men to determine the positive and negative predictive values of mpMRI for EPE at radical prostatectomy for different prostate cancer risk groups. The overall prevalence of EPE at radical prostatectomy was 49.7% (24.7% low-risk; 77.1% high-risk) – the overall staging sensitivity was 58.2%, specificity was 89.1%, positive predictive value was 84.1% and a negative predictive value was 68.3%. The positive predictive value was best in the high-risk cohort (88.8%) and a negative predictive value was best in the low-risk cohort (87.7%).

Data regarding whether preoperative imaging influences surgical planning is limited. However, Schiavina et al.25 assessed the impact of mpMRI on preoperative decision making among 137 patients planned for radical prostatectomy who underwent mpMRI. They found that mpMRI changes robotic surgeon’s initial surgical plan with regards to the degree of nerve-sparing in nearly half of patients. Interestingly, there was an equal alteration in surgical planning when considering a more aggressive (to less aggressive) and less aggressive (to more aggressive) preliminary plan. Although the above results for EPE prediction and tailored surgical planning are encouraging, this degree of advanced mpMRI interpretation should be reserved for expert radiologists where sensitivities and specificities for predicting EPE are typically both >80%.26

Conclusions

The improvement of MRI technology and development of mpMRI for prostate imaging is one of the most important technologic advancements in urologic oncology over the past decade. The PROMIS and PRECISION trials have delineated the utility of mpMRI among men considering a prostate biopsy. Likely the most accepted and concrete indication for utilization of mpMRI is in men with a negative prostate biopsy and persistent/increasingly elevated PSA, specifically to enhance the ability to detect previously unsampled (often anterior) tumors. The recent EAU statement on active surveillance has provided much-needed guidance as to when to include mpMRI in the surveillance algorithm; work is still necessary to delineate who benefits from serial mpMRI, particularly after 1 year on active surveillance. Finally, there is increased utilization of mpMRI among patients planned for radical prostatectomy to assess the degree of acceptable nerve sparing without compromising oncologic efficacy, however the high-level of mpMRI interpretation to accurately assess EPE in these instances requires expert radiologic experience.

Published Date: April 16th, 2019
Written by: Zachary Klaassen, MD, MSc
References: 1. Muller BG, Futterer JJ, Gupta RT, Katz A, Kirkham A, Kurhanewicz J, et al. The role of magnetic resonance imaging (MRI) in focal therapy for prostate cancer: recommendations from a consensus panel. BJU Int. 2014;113:218-27.
2. Rosenkrantz AB, Kopec M, Kong X, Melamed J, Dakwar G, Babb JS, et al. Prostate cancer vs. post-biopsy hemorrhage: diagnosis with T2- and diffusion-weighted imaging. J Magn Reson Imaging. 2010;31:1387-94.
3. Abd-Alazeez M, Kirkham A, Ahmed HU, Arya M, Anastasiadis E, Charman SC, et al. Performance of multiparametric MRI in men at risk of prostate cancer before the first biopsy: a paired validating cohort study using template prostate mapping biopsies as the reference standard. Prostate Cancer Prostatic Dis. 2014;17:40-6.
4. Barentsz JO, Weinreb JC, Verma S, Thoeny HC, Tempany CM, Shtern F, et al. Synopsis of the PI-RADS v2 Guidelines for Multiparametric Prostate Magnetic Resonance Imaging and Recommendations for Use. Eur Urol. 2016;69:41-9.
5. Thompson JE, Moses D, Shnier R, Brenner P, Delprado W, Ponsky L, et al. Multiparametric magnetic resonance imaging guided diagnostic biopsy detects significant prostate cancer and could reduce unnecessary biopsies and over detection: a prospective study. J Urol. 2014;192:67-74.
6. Thompson JE, van Leeuwen PJ, Moses D, Shnier R, Brenner P, Delprado W, et al. The Diagnostic Performance of Multiparametric Magnetic Resonance Imaging to Detect Significant Prostate Cancer. J Urol. 2016;195:1428-35.
7. Ahmed HU, El-Shater Bosaily A, Brown LC, Gabe R, Kaplan R, Parmar MK, et al. Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet. 2017;389:815-22.
8. Kasivisvanathan V, Rannikko AS, Borghi M, Panebianco V, Mynderse LA, Vaarala MH, et al. MRI-Targeted or Standard Biopsy for Prostate-Cancer Diagnosis. N Engl J Med. 2018;378:1767-77.
9. Nzenza T, Murphy DG. PRECISION delivers on the PROMIS of mpMRI in early detection. Nat Rev Urol. 2018.
10. Hoeks CM, Schouten MG, Bomers JG, Hoogendoorn SP, Hulsbergen-van de Kaa CA, Hambrock T, et al. Three-Tesla magnetic resonance-guided prostate biopsy in men with increased prostate-specific antigen and repeated, negative, random, systematic, transrectal ultrasound biopsies: detection of clinically significant prostate cancers. Eur Urol. 2012;62:902-9.
11. Kirkham AP, Haslam P, Keanie JY, McCafferty I, Padhani AR, Punwani S, et al. Prostate MRI: who, when, and how? Report from a UK consensus meeting. Clin Radiol. 2013;68:1016-23.
12. Lawrentschuk N, Fleshner N. The role of magnetic resonance imaging in targeting prostate cancer in patients with previous negative biopsies and elevated prostate-specific antigen levels. BJU Int. 2009;103:730-3.
13. Hambrock T, Somford DM, Hoeks C, Bouwense SA, Huisman H, Yakar D, et al. Magnetic resonance imaging guided prostate biopsy in men with repeat negative biopsies and increased prostate specific antigen. J Urol. 2010;183:520-7.
14. Zugor V, Kuhn R, Engelhard K, Poth S, Bernat MM, Porres D, et al. The Value of Endorectal Magnetic Resonance Imaging of the Prostate in Improving the Detection of Anterior Prostate Cancer. Anticancer Res. 2016;36:4279-83.
15. Kongnyuy M, Sidana A, George AK, Muthigi A, Iyer A, Fascelli M, et al. The significance of anterior prostate lesions on multiparametric magnetic resonance imaging in African-American men. Urol Oncol. 2016;34:254 e15-21.
16. Scarpato KR, Barocas DA. Use of mpMRI in active surveillance for localized prostate cancer. Urol Oncol. 2016;34:320-5.
17. Briganti A, Fossati N, Catto JWF, Cornford P, Montorsi F, Mottet N, et al. Active Surveillance for Low-risk Prostate Cancer: The European Association of Urology Position in 2018. Eur Urol. 2018;74:357-68.
18. Schoots IG, Petrides N, Giganti F, Bokhorst LP, Rannikko A, Klotz L, et al. Magnetic resonance imaging in active surveillance of prostate cancer: a systematic review. Eur Urol. 2015;67:627-36.
19. Recabal P, Assel M, Sjoberg DD, Lee D, Laudone VP, Touijer K, et al. The Efficacy of Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Imaging Targeted Biopsy in Risk Classification for Patients with Prostate Cancer on Active Surveillance. J Urol. 2016;196:374-81.
20. Pessoa RR, Viana PC, Mattedi RL, Guglielmetti GB, Cordeiro MD, Coelho RF, et al. Value of 3-Tesla multiparametric magnetic resonance imaging and targeted biopsy for improved risk stratification in patients considered for active surveillance. BJU Int. 2017;119:535-42.
21. Hamoen EHJ, Hoeks CMA, Somford DM, van Oort IM, Vergunst H, Oddens JR, et al. Value of Serial Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Imaging-guided Biopsies in Men with Low-risk Prostate Cancer on Active Surveillance After 1 Yr Follow-up. Eur Urol Focus. 2018.
22. Walton Diaz A, Shakir NA, George AK, Rais-Bahrami S, Turkbey B, Rothwax JT, et al. Use of serial multiparametric magnetic resonance imaging in the management of patients with prostate cancer on active surveillance. Urol Oncol. 2015;33:202 e1- e7.
23. Klotz L, Loblaw A, Sugar L, Moussa M, Berman DM, Van der Kwast T, et al. Active Surveillance Magnetic Resonance Imaging Study (ASIST): Results of a Randomized Multicenter Prospective Trial. Eur Urol. 2018.
24. Somford DM, Hamoen EH, Futterer JJ, van Basten JP, Hulsbergen-van de Kaa CA, Vreuls W, et al. The predictive value of endorectal 3 Tesla multiparametric magnetic resonance imaging for extraprostatic extension in patients with low, intermediate and high risk prostate cancer. J Urol. 2013;190:1728-34.
25. Schiavina R, Bianchi L, Borghesi M, Dababneh H, Chessa F, Pultrone CV, et al. MRI Displays the Prostatic Cancer Anatomy and Improves the Bundles Management Before Robot-Assisted Radical Prostatectomy. J Endourol. 2018;32:315-21.
26. Tay KJ, Gupta RT, Brown AF, Silverman RK, Polascik TJ. Defining the Incremental Utility of Prostate Multiparametric Magnetic Resonance Imaging at Standard and Specialized Read in Predicting Extracapsular Extension of Prostate Cancer. Eur Urol. 2016;70:211-3.

The Current Status of Stereotactic Body Radiation Therapy in Kidney Cancer

Renal cancers are common, accounting for an estimated 65,340 new diagnoses and 14,970 attributable death in 2018 in the United States.1 The “Epidemiology and Etiology of Kidney Cancer” is discussed at length in the linked article in the UroToday Center of Excellence series. Despite a large number of histologic tumor types that may occur in the kidney, renal cell carcinoma (RCC) is the most prevalent histology and this article will focus on patients with RCC.

There are a number of accepted treatment options for patients diagnosed with localized RCC. These include radical nephrectomy (whether open, laparoscopic or robotic), partial nephrectomy (whether open, laparoscopic, or robotic), surgical or non-surgical ablation, and active surveillance. The most appropriate treatment strategy will depend on patient (host) and tumor characteristics. These details are discussed more fully in the “Malignant Renal Tumors” article in the UroToday Center of Excellence series.

Kidney cancer has been historically thought of as a “radio-resistant” tumor. This is based on in vitro studies2 as well as the fact that early trial of adjuvant and neoadjuvant radiotherapy in patients with RCC undergoing surgical resection failed to show benefit.3,4  As a result, traditionally fractionated radiotherapy has been historically limited to palliative intent for patients with RCC. However, hypofractionated, high-dose radiotherapy has proven successful in the local control of RCC metastasis to the brain and other bony and visceral sites (refs 6-15). Coinciding with these clinical data was the emergence of data demonstrating the efficacy of high dose per fraction radiotherapy in the treatment of RCC in a mouse model.5 This led to increasing interest in the use of stereotactic body radiotherapy (SBRT) in the treatment of localized RCC. SBRT is routinely used for the treatment of malignancies of other tissue types including lung, liver, spine, and prostate.6 Compared to other radiation techniques, SBRT utilizes a smaller number of higher dose fractions. This is believed to assist with overcoming the previously believed radioresistance of RCC. Further, compared to other ablative approaches, one of the advantages of SBRT is the ability to treat larger lesions.6

Given uncertainties about both the efficacy and toxicity of such an approach, initial investigation has focused on patients in whom extirpative surgery, the gold standard approach, is not feasible or safe.

There are currently both retrospective and prospective reports characterising outcomes for patients treated with SBRT for localized RCC. These studies include a variety of treatment approaches including single fraction treatment (often 26 Gy in 1 fraction) and multiple fraction regimes (including regimes ranging from 2 to 10 fractions and total doses ranging from 5 to 85 Gy). As may be expected from some different treatment approaches, there are differences in both efficacy and toxicity between studies.

Prospective cohort studies

A recent systematic review identified eight published prospective studies of SBRT in the treatment of patients with localized RCC.7 Apart from one study published in 2006, the remainder have been published in the last five years. The strength of conclusions that can be drawn from these data are limited by small sample sizes (4 to 40 patients with localized RCC per study) and limited follow-up (13 to 52 months, with most 2 years or less).7 In addition, as previously mentioned, there were significant differences in total dose delivered and radiotherapy prescription between studies.

In each case, the authors report on patients who were either deemed medically inoperable, at very high risk for surgery due to the risk of dialysis or who refused surgery. Some studies had specific, disease-related criteria (e.g. a single lesion, maximal tumor dimension less than 4 or 5 cm) whereas this was not specified in other manuscripts. Outcomes were variably reported with local control most often reported. Additionally, adverse events were variously, and non-systematically reported.

Local control rates varied, in large part in correlation to the duration of observation: from 87% local control rate at a median 37 months follow up to 100% at two years in one trial8. Notably, even in the publication from Siva and colleagues who reported 100% local control, 10% of patients experienced distant progression, an outcome that is more likely to contribute to morbidity and mortality than local recurrence.8 Longer-term outcomes remain to be assessed.

Likely due in part to differing radiotherapy prescriptions, toxicity rates varied significantly. Both Siva and colleagues and Svendman and colleagues reported grade 1-2 toxicity in more than 50% of patients, most notably characterized by chest wall pain, nausea, and fatigue.8,9 In addition to considerations regarding comorbidity, SBRT and other non-surgical approaches to renal masses are often considered in patients with poor renal function for whom nephron preservation is a top priority. Thus, post-procedural renal function is an important outcome and, again, results vary between reports. Kaplan and colleagues reported worsening of renal function in 2 of 12 patients undergoing SBRT for medically inoperable tumors less than 5cm.10 McBride et al., in a similar population of patients, found that 2 of 15 patients (13%) had late grade 3 renal dysfunction with a mean decrease in glomerular filtration rate of 18 mg/dL among the whole study population.11 Similarly, Ponsky and colleagues demonstrated an 11% rate of grade 3 renal dysfunction among 19 patients deemed poor surgical candidates who received SBRT.12 Finally, and perhaps more optimistically, Siva and colleagues found in their cohort of 21 patients that the average decrease in glomerular filtration rate was only 8.7 mL/min at one year following treatment.8. Taken together, evidence suggests that increased fractionation (as in 20 to 30 Gy in 10 fractions) was strongly correlated with renal atrophy.13

Taken together, these data suggest that, for patients who receive three radiation fractions, a minimum per fraction dose of 11 Gy should be administered as this was the minimum dose that, in prospective cohorts, no patient experienced local failure.7 

Retrospective cohort studies


In addition to the aforementioned prospective cohort studies, there are a number of retrospective cohort studies examining the use of SBRT in primary RCC. These, for the most part, have the same limitations are the prospective studies including limited sample size, short follow-up and heterogeneity of radiotherapy prescription. While most of these reports demonstrated local control rates comparable to the prospective literature (93 – 100%), one study demonstrated significantly lower local control (65%) among patients who had a history of radical nephrectomy for RCC in the contra-lateral kidney14. Those patients received 60 to 85 Gy in 5 to 7 fractions using stereotactic gamma-ray irradiation.

Patient selection

Surgery remains the mainstay of curative-intent treatment for patients with localized RCC. Ablative approaches, including SBRT, may, therefore, be considered among patients for whom surgery is contraindicated or who refuse surgery. Recent guidelines have recommended emphasizing that SBRT remains an experimental option in RCC due to the relatively limited worldwide experience and lack of long-term data.15

Treatment recommendations

The International Radiosurgery Oncology Consortium for Kidney performed a 65 item survey among eight institutions who performed SBRT for primary RCC.16 A number of important conclusions came out of this work and the resulting consensus statement. First, all included centers treat patients with solitary kidneys or pre-existing hypertension. Five of the eight institutions have size cut off criteria ranging from 5 to 8 cm in maximal tumor dimension. The total planning target volume expansion varied between institutions, ranging from 3 to 10 mm. While all centers used pretreatment image verification, seven of the eight utilized intrafractional monitoring of some sort. Radiation prescriptions varied from 1 to 12 fractions with a total dose of 25 to 80 Gy. However, the consensus statement recommends a total dose of 36 to 45 Gy for patients receiving 3 fraction regimes and 40 to 50 Gy for patients receiving 5 fraction regimes. Obviously, the size of the primary tumour and its proximity to critical and adjacent structures will influence the total dose and fractionation regime.

Ongoing surveillance follow-up for local tumor response and recurrence varied with some institutions relying on computed tomography (CT) alone while others used magnetic resonance imaging (MRI) or PET-CT. Typically, follow-up was performed every three to six months in the first two years and every three to twelve months in the subsequent three years.

One of the challenges in the post-treatment monitoring of these patients is the interpretation of radiographic studies and identification of imaging studies. Among 41 tumours treated with SBRT, the largest available study of imaging characteristics following treatment found that the linear growth rate regressed by an average of 0.37 cm per year after treatment but that there were no significant changed in enhancement when comparing imaging before and following treatment.17

Conclusions


Stereotactic body radiotherapy is an emerging treatment approach for patients with primary renal cell carcinoma. Compared to other ablative approaches (such as radiofrequency ablation or cryotherapy), it offers the opportunity to treat larger tumors and potentially those in closer proximity to critical structures. To date, surgical extirpation via partial or radical nephrectomy remains the gold standard and SBRT has primarily been investigated among patients who are either deemed medically inoperable or who refuse surgery. There are a number of ongoing studies assessing the role of SBRT that will increase the prospective global experience with this approach, however, none will provide comparative data with other treatment approaches. One particular area of interest in the potential for synergistic effects between SBRT and systemic therapy, particularly immunotherapy (ClinicalTrials.gov identifiers: NCT01896271, NCT02781506, NCT02306954, and NCT02334709).

Published Date: November 2019
Written by: Zachary Klaassen, MD MSc
References: References:
1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2018. CA Cancer J Clin 2018; 68(1):7-30.
2. Deschavanne PJ, Fertil B. A review of human cell radiosensitivity in vitro. Int J Radiat Oncol Biol Phys 1996; 34(1):251-66.
3. Finney R. The value of radiotherapy in the treatment of hypernephroma--a clinical trial. Br J Urol 1973; 45(3):258-69.
4. Juusela H, Malmio K, Alfthan O, et al. Preoperative irradiation in the treatment of renal adenocarcinoma. Scand J Urol Nephrol 1977; 11(3):277-81.
5. Walsh L, Stanfield JL, Cho LC, et al. Efficacy of ablative high-dose-per-fraction radiation for implanted human renal cell cancer in a nude mouse model. Eur Urol 2006; 50(4):795-800; discussion 800.
6. Francolini G, Detti B, Ingrosso G, et al. Stereotactic body radiation therapy (SBRT) on renal cell carcinoma, an overview of technical aspects, biological rationale and current literature. Crit Rev Oncol Hematol 2018; 131:24-29.
7. Miccio J, Johung K. When Surgery Is Not an Option in Renal Cell Carcinoma: The Evolving Role of Stereotactic Body Radiation Therapy. Oncology (Williston Park) 2019; 33(5):167-73, 177.
8. Siva S, Pham D, Kron T, et al. Stereotactic ablative body radiotherapy for inoperable primary kidney cancer: a prospective clinical trial. BJU Int 2017; 120(5):623-630.
9. Svedman C, Sandstrom P, Pisa P, et al. A prospective Phase II trial of using extracranial stereotactic radiotherapy in primary and metastatic renal cell carcinoma. Acta Oncol 2006; 45(7):870-5.
10. Kaplan ID, Redrosa I, C. M, et al. Results of a phase I dose escalation study of stereotactic radiosurgery for primary renal tumors. Int J Radiat Oncol Biol Phys 2010; 78:S191.
11. McBride SM, Wagner AA, Kaplan ID. A phase 1 dose-escalation study of robotic radiosurgery in inoperable primary renal cell carcinoma. Int J Radiat Oncol Biol Phys 2013; 87:S84.
12. Ponsky L, Lo SS, Zhang Y, et al. Phase I dose-escalation study of stereotactic body radiotherapy (SBRT) for poor surgical candidates with localized renal cell carcinoma. Radiother Oncol 2015; 117(1):183-7.
13. Yamamoto T, Kadoya N, Takeda K, et al. Renal atrophy after stereotactic body radiotherapy for renal cell carcinoma. Radiat Oncol 2016; 11:72.
14. Wang YJ, Han TT, Xue JX, et al. Stereotactic gamma-ray body radiation therapy for asynchronous bilateral renal cell carcinoma. Radiol Med 2014; 119(11):878-83.
15. Muller AC, van Oorschot B, Micke O, et al. [German S3 guideline for renal cell carcinoma : Presentation and discussion of essential aspects for the radiation oncologist]. Strahlenther Onkol 2018; 194(1):1-8.
16. Siva S, Ellis RJ, Ponsky L, et al. Consensus statement from the International Radiosurgery Oncology Consortium for Kidney for primary renal cell carcinoma. Future Oncol 2016; 12(5):637-45.
17. Sun MR, Brook A, Powell MF, et al. Effect of Stereotactic Body Radiotherapy on the Growth Kinetics and Enhancement Pattern of Primary Renal Tumors. AJR Am J Roentgenol 2016; 206(3):544-53.

Nocturia: A Nighttime Condition with Daytime Consequences

Michael, a 61-one-year old executive accountant, presents for annual PSA monitoring and digital rectal examination. He reports that alpha-blocker therapy using tamsulosin has improved his benign prostatic hypertrophy, but that he still wakes frequently at night to void. He is otherwise healthy except for a history of type 2 diabetes mellitus that is well controlled with metformin. He views his nighttime trips to the bathroom as a normal part of aging (“all my friends have the same problem”). Michael’s wife, who has attended the appointment with him, interjects that Michael’s trips to the bathroom wake her and so she is tired during the day. On further questioning, Michael reports that he has trouble concentrating during his many meetings, and that he feels tired and sleepy during his drive home from work. How might we best manage his care?

Michael’s case mirrors those seen frequently in many urology practices. Nocturia, the most common lower urinary tract symptom affecting men and women of all ages, has numerous negative effects on physical and mental health, productivity, and quality of life.4 At the same time, prevailing misconceptions and a historic lack of safe, effective therapies for nocturia have created a striking treatment gap. 4,34,35,48 In this article, we review the definition, prevalence, and etiologies of nocturia and behavioral and medical treatment options. We then focus on the clinical profile and development of NOCTIVATM (desmopressin acetate), a proprietary and novel nasal spray of vasopressin analog that is the first medication approved in the United States for adults with nocturia due to overproduction of urine at night.5,32 We conclude by discussing practical strategies for the safe, effective initiation and continuation of NOCTIVATM therapy in clinical practice.

Definition and Epidemiology 

The International Continence Society (ICS) defines nocturia as waking at least once at night to void, with each void preceded and followed by sleep.3 This definition excludes first morning void (the first void after waking with the intention to rise).3 Left untreated, nocturia significantly reduces daytime functioning, mood, and quality of life, and increases the risk of falls, injuries, and mortality. 4,6,8,42,28 Multiple studies indicate that waking just twice at night to void is bothersome and has clinically significant effects.76,2,16,13 Thus, when considering nocturia as a condition of the lower urinary tract, voiding two or more times a night is viewed as clinically meaningful.

Despite these serious consequences, nocturia has been chronically understudied, underdetected, and underreported. 4 Patients often do not disclose their nocturia to healthcare providers because they are reluctant to discuss toileting or do not connect their nocturia with other signs and symptoms they may be experiencing.41,51 Additionally, many patients, and some clinicians, misperceive nocturia as a benign and natural part of aging or as merely a symptom of benign prostatic hypertrophy in males or overactive bladder in males and females.25

In reality, nocturia frequently arises independently of overactive bladder and benign prostatic hypertrophy and is the most common lower urinary tract symptom affecting adults of both sexes and all ages.4,6,8,26,49,50,51,52,18

In a systematic review and meta-analysis of 43 studies published between 1990 and 2009, between 2% and 18% of adults in their 20s to 40s reported waking at least twice nightly to void, as did 29% to 59% of men and 28% to 61.5% of women aged 70 and older.26 In another study of more than 5,200 men participating in the National Health and Nutrition Examination Survey (NHANES), the prevalence of nocturia ranged from 8.2% among those aged 20 to 34 years to 55.8% among those aged 75 years or more.18

Nocturia also is highly prevalent among adults from diverse ethnic groups. In a population-based study of rural community health centers in Korea, 87% of men and 86% of women aged 65 years and older reported waking at least once nightly to void.49 In another population-based study of more than 4,100 adults aged 40 years and older in China, approximately 75% of individuals reported waking at least once per night to void and more than 33% did so at least twice nightly.51 In a population-level study of reproductive-aged women in Turkey, approximately one-third of those in their 20s and 30s reported waking at least once per night to void, as did approximately 46% of women in their 40s.56 Finally, in a population-based study of female primary care patients aged 18 to 85 years in Brazil, approximately 58% reported waking at least once nightly to void.52

Consequences of Nocturia 

The many negative effects of nocturia hinge on its impact on sleep. Sleep consists of two main states: rapid eye movement (REM) sleep, which comprises approximately 25% of total sleep time and is implicated in mental functioning, and non-REM (NREM) sleep, which makes up approximately 75% of total sleep time and is concerned with homeostatic processes.14,60

Importantly, NREM sleep includes four stages: the transition from wakefulness to sleep (stage 1), light sleep (stage 2), and deep, restorative, slow-wave sleep (stages 3 and 4).14 Because stages 3 and 4 occur during the first 4 hours of sleep, waking during this time decreases restorative slow-wave sleep even if there are no major changes in REM and NREM time. 14,60 Persons who wake at least twice per night in order to void usually sleep only 2 to 3 hours before their first trip to the bathroom.6,15 This curtails their first uninterrupted sleep period, which reduces slow-wave sleep and leads to greater daytime fatigue and sleepiness, a lower pain threshold, longer reaction times, and reductions in psychomotor performance, attention span, and memory.19,78,7

Nocturia is usually a chronic condition. The repetitive nature of the sleep disruption is likely why nocturia also significantly increases the risk of somatic diseases, emotional symptoms, motor vehicle accidents, falls, fractures, and mortality.19,62,59,65,66,67,20,22,68 In a large cross-sectional study of adults in the United States, nocturia correlated strongly with cardiovascular disease, hypertension, and stroke, even after controlling for known confounders such as comorbid diabetes and respiratory sleep disorders.62 In another large study of adults in Minnesota, nocturia was independently associated with coronary heart disease among men younger than 60 years.23 Other studies have linked poor sleep due to nocturia with immune and inflammatory dysregulation and aberrant glucose metabolism, which in turn are associated with diabetes mellitus, the metabolic syndrome, cardiovascular disease, and numerous other chronic diseases.63,64,59

Researchers also have linked nocturia with an increased risk for anxiety and mood disorders. A recent review of 12 population-based studies identified a bidirectional association between nocturia and depression and anxiety.57 In another study of more than 5,500 adults who responded to the Boston Area Community Health survey, the severity of nocturia correlated with depression among both men and women, even after controlling for covariates such as age, ethnicity, smoking, and socioeconomic status.17 Although the association was strongest among younger individuals, nocturia increased the odds of depression more than three-fold among women reporting sleep disturbances due to urologic symptoms (adjusted odds ratio [OR], 3.37; 95% confidence interval [CI], 1.63-6.94). 17 Finally, in a population-based study of rural Koreans, individuals with nocturia reported adverse emotional effects, lower energy levels, and reduced daytime functioning.49

Falls during nighttime toileting increase the risk of fracture and mortality, and these risks increase with increasing numbers of nocturic episodes per night.20 In a recent longitudinal study of approximately 1,800 middle-aged and older men who were followed for an average of 6.2 years, rates of hip fracture were 2.7% among men who rose at least twice nightly to void but only 1.0% among men who rose once nightly and 0.9% among men without nocturia. Rising at least twice per night to void significantly increased the risk of hip fracture regardless of age (adjusted OR, 1.36; 95% CI, 1.03-1.80; P=.03).68 In another 5-year observational study of elderly adults in Japan, those with two or more nocturic episodes per night were at significantly increased risk of falls leading to fracture (hazard ratio [HR], 2.20; 95% CI, 1.04-4.68; P=.04) and death (HR, 1.91, 95% CI, 1.07-3.43; P=.03).22 Nocturia remained a significant risk factor for mortality even after controlling for smoking, comorbidities, and medications that increase the likelihood of falls, such as tranquilizers and hypnotics (HR, 1.98, 95% CI, 1.09-3.59; P=.03). 22

Several other studies also have linked nocturia with an increased risk for mortality. 23,21 In a multivariate analysis of NHANES data from adults aged 20 years and older, awakening at least twice nightly to void correlated significantly with mortality, particularly among individuals younger than 65 years.21 The study authors hypothesized that the health effects of chronic sleep disruption from nocturia ultimately increased the risk of death.

Finally, clinically significant nocturia can erode nearly all aspects of health-related quality of life. In a study of more than 3,500 adults in Finland aged 18 to 79 years, those with at least two nocturic episodes per night scored significantly lower on 14 of 15 dimensions of health-related quality of life as measured by the generic 15D instrument.13 The negative effects of nocturia were similar in both genders. 13 In another recent qualitative study of 20 adults in the United States who averaged three nocturic episodes per night, nocturia was associated with high levels of daytime fatigue, poor emotional well-being, and reduced social and cognitive functioning that limited respondents’ ability to work and perform daily activities.43

The adverse effects of the chronic nature of nocturia are costly. In a recent study, researchers analyzed data from the Boston Area Community Health Study, the U.S. Bureau of Labor Statistics, and the Work Productivity and Impairment questionnaire.42 They concluded that at least 28 million U.S. adults rise at least twice nightly to void, incurring 127 lost hours of productivity per person every year, $61 billion in economic losses, and at least $1.5 billion in health care costs related to falls.42

Etiologies and Assessment of Nocturia 

The assessment of patients with nocturia should begin with a thoughtful consideration of its etiology or etiologies. It is helpful to keep in mind that awakening (or not) because of the need to void is a product of the relationship between the amount of urine produced at night and the ability of the bladder to store it.9 Normal nocturnal bladder capacity depends on many factors, including near-complete bladder emptying, low nighttime intracystic pressure, normal bladder sensation during filling, adequate sphincter function (no stress incontinence), a lack of involuntary contractions (no bladder overactivity), and a lack of excess urine production at night.9,10,78, 4,11,12 Derangements in any of these variables can lead to clinically significant nocturia.

Thus, nocturia can result from nocturnal or global polyuria, bladder storage problems, psychologic factors and sleep disturbances, fluid intake behaviors, medications, or mixed syndromes.27,24,29,3,30,31 Among these etiologies, by far the most prevalent is nocturnal polyuria, which the International Continence Society defines as the nighttime production of more than 33% of total 24-hour urine volume by adults aged 65 years and older, and the nighttime production more than 20% of total 24-hour urine volume by younger adults.3,30 Nocturnal polyuria becomes more common with age, but it is the most common cause of nocturia in all age groups has been implicated in up to 80% of cases of nocturia.27,25,3

It is important to distinguish nocturnal polyuria from global polyuria, defined as total 24-hour urine output greater than 40 mL per kg of body weight.3,30 A frequency-volume assessment helps differentiate these two syndromes: Patients record the time and volume of each void, typically for 3 days.25 The sum of each nighttime void volume and the first morning void volume is then divided by the total 24-hour urine volume.

When evaluating a nocturic adult, physicians also should consider the possible role of fluid intake behaviors, congestive heart failure, type 2 diabetes, peripheral edema due to venous disease, overactive bladder (increased urinary urgency and frequency that may or may not involve nocturia) in men and women, and benign prostatic hypertrophy in men.45  Mood and anxiety disorders are common comorbidities; it is helpful to ask if patients are waking because they need to void or are deciding to use the bathroom once awake (nocturnal convenience void).53 Short, self-administered screening tools such as the Hospital Anxiety and Depression Scale (HADS) and the Geriatric Depression Scale (GDS) are not commonly used in urology practice but are feasible to deploy and can help identify patients whose nocturia and overall well-being might benefit from mental health care.57,58

Physicians should also ask nocturic patients about respiratory sleep disorders, which are another common comorbidity.45 In particular, obstructive sleep apnea causes pulmonary vasoconstriction and hypoxia, leading to increased atrial natriuretic peptide levels, renal sodium and water excretion, and nocturia.53 In recent prospective and retrospective studies of adults with obstructive sleep apnea, severity correlated with nocturic episodes per night, and patients who were treated with continuous positive airway pressure (CPAP) showed a subsequent improvement in nocturia.46,47

In summary, when assessing patients with nocturia, it is important to keep in mind that nocturnal polyuria is very often the cause, but also to look for global polyuria, overactive bladder, benign prostatic hypertrophy, and somatic, psychiatric, and respiratory sleep disorders. Nocturia is complex and multifactorial; a tailored approach to management maximizes the likelihood of treatment response and should involve multidisciplinary approaches, when appropriate.

Treatment Considerations 

Conventionally, the management of nocturia begins with lifestyle changes and behavioral therapy. Patients should be encouraged to restrict fluid intake after early evening, restrict caffeine and alcohol, take diuretics in the mid-afternoon, elevate their legs in the evening to help mobilize fluids, and void immediately before bed. However, behavior modification alone tends to be ineffective and not durable.25,33 Patients usually cannot maintain such extensive lifestyle changes, and fluid restriction is ineffective if patients have subnormal levels of circulating vasopressin.34,35,10

Unfortunately, there also has been a historic lack of safe, effective medications for nocturia. Approved treatments for overactive bladder and benign prostatic hypotrophy have been prescribed off-label for nocturia but are usually ineffective. This is because nocturia is primarily a “kidney” condition; most cases are due to nocturnal polyuria, or the excessive production of urine at night by the kidneys due to alterations in circulating vasopressin.29,25 Medications for overactive bladder and benign prostatic hypertrophy target “downstream” organs: the bladder (anticholinergics/antimuscarinics and β3-adrenergic agonists) and the prostate gland (⍺-blockers).39,40,41,33,24,25

A more effective approach to treating nocturia is to administer a synthetic analog of vasopressin. Vasopressin or antidiuretic hormone acts on V receptors 1, 2, and 3) to induce vasoconstriction, osmoregulation, and corticotropin secretion.69 In the renal collecting tubule, vasopressin activates the V2 receptor, which increases production of the aquaporin-2 water channel and its migration to the apical plasma membrane.54 The result is greater osmotic water permeability, increased water reabsorption in the distal tubule and collecting ducts, and decreased urine production.55,53

Desmopressin is a synthetic analog of arginine vasopressin that selectively targets the V2 receptor, thereby retaining the antidiuretic properties of vasopressin without exhibiting its unwanted pressor activity.25 Desmopressin was first approved in the United States in oral form.36 In a systematic review and meta-analysis of 10 randomized trials comparing oral desmopressin or placebo in 2,191 healthy adults with nocturia, desmopressin (100 micrograms [mcg]) extended the first uninterrupted sleep period by more than 1 hour in most patients and decreased nocturic episodes by a mean of 0.72 events per night.38 Compared with placebo, however, desmopressin was associated with a five-fold increase in the risk of hyponatremia at doses of 10 mcg or more (relative risk, 5.1; 95% CI, 3.0-8.8).38 In two other randomized trials of oral desmopressin in nocturic women and men, 34% and 46% of treated patients had fewer than half the number of voids compared with baseline, compared with 3% of 7% of patients in the placebo groups.35,37

These efficacy data for desmopressin are important because improving or resolving clinically significant nocturia can significantly improve sleep architecture, leading to more restorative sleep. In a recent post-hoc analysis of data from three clinical trials of 841 nocturic adults (90% of whom had nocturnal polyuria), treatment with desmopressin was associated with significant increases in first uninterrupted sleep period, even after accounting for numerous demographic and clinical covariates.61 In another post-hoc analysis of clinical trial data, treatment with desmopressin lengthened first uninterrupted sleep period, leading to improvements on nearly all subscales of the Pittsburgh Sleep Quality Index.75 Finally, in a study of 105 men treated for nocturia, those who responded to treatment (waking at least once less during the night to void) experienced a 1.8-hour mean increase in first uninterrupted sleep period, while non-responders averaged a 0.6-hour decrease in first uninterrupted sleep period during follow-up.

However, oral desmopressin tablets are not FDA-approved for the treatment of nocturia due to nocturnal polyuria and are seldom used in urology practice.81,Barkin,48 In a recent retrospective study of 403 adults seen in tertiary urology practice for the primary complaint of nocturia, 76% of patients had nocturnal polyuria but only 5% used oral desmopressin.48 Notably, the completion of bladder diaries did not improve nocturia, underscoring the limitations of behavioral therapy.48 A sublingual melt formulation of desmopressin has recently been approved by the FDA for the treatment of nocturia in adults but is not yet commercially available.80 Likewise, an older intranasal spray formulation of desmopressin been found to improve nocturnal polyuria in men with benign prostatic hypertrophy.53,70 but is not approved for the treatment of nocturia.31

NOCTIVA 

In March 2017, the U.S. Food and Drug Administration approved NOCTIVA for the treatment of nocturia due to nocturnal polyuria in adults who awaken at least twice nightly to void.79 NOCTIVA is a preservative-free proprietary emulsification of desmopressin acetate and cyclopentadecanolide, a permeation enhancer that facilitates rapid absorption of desmopressin across the nasal mucosa and allows for use of a lower dose.79,5, 1 The bottle is also designed to deliver a unique spray pattern that maximizes the distribution of the emulsification throughout the nasal cavity. These unique characteristics of NOCTIVA facilitate microdosing, rapid absorption, and pharmacokinetic consistency from dose to dose. Two FDA-approved dosing bottles are available: NOCTIVA 1.66 mcg and NOCTIVA 0.83 mcg.

The NOCTIVA development program included 10 studies: two phase 1 trials, one phase 2 trial, four phase 3, double-blind, placebo-controlled trials, one phase 3 open-label study in elderly patients, and two open-label, long-term safety extension trials.74 In this article, we focus on the results of the most recent double-blind phase 3 trials and the long-term extension trials.

Pivotal Trials: Design and Patients 

The safety and efficacy of NOCTIVA 1.66 mcg and NOCTIVA 0.83 mcg were evaluated in two multicenter, randomized, double-blind, placebo-controlled phase 3 trials (DB3 and DB4). 1 The intention-to-treat population consisted of 1,333 adults aged 50 years and older who averaged 3.3 nocturic voids per night during screening.

Co-primary endpoints in both trials were change from baseline in mean number of nocturic episodes per night and percentage of patients achieving at least a 50% reduction in nocturic episodes per night.

Secondary efficacy endpoints included nocturnal urine volume, first uninterrupted sleep period (time from bedtime to the first nocturic void), percentage of nights in which patients had one or no nocturic voids.

The DB4 study also assessed the change from baseline in scores on the Impact of Nighttime Urination (INTU) questionnaire, a validated 10-item tool that assesses the clinical meaningfulness (based on patient perceptions) of reducing nocturic episodes per night.71,72  The daytime impact domain of the INTU tool assesses concentration, tiredness, ability to complete activities, irritability, restfulness, and daytime drowsiness, while the nighttime domain assesses bother, premature waking, insufficient sleep, and level of emotional concern about needing to get out of bed to urinate. The overall score ranges from 0 to 100, with 100 representing the greatest detrimental impact of nocturia. Patients in the DB4 study completed three INTU questionnaires that corresponded with three voiding diaries.

During the 2-week lead-in periods, patients received intranasal placebo spray every night and completed two 3-day nightly voiding diaries. At[DR1]  the end of the lead-in periods, all patients were randomly assigned to receive NOCTIVA 1.66 mcg (containing  0.75 mcg desmopressin), NOCTIVA 0.83 mcg (containing 1.5 mcg desmopressin), or placebo. Study drug and placebo were administered intranasally every night, and efficacy and safety assessments were performed every 2 weeks. 1 No fluid restrictions or other behavioral changes were imposed on study participants. The second trial (DB4) also evaluated an intermediate dose of NOCTIVA containing 1.0 mcg desmopressin .

Most (57%) trial participants were male, and mean age was 66 years (range, 50-90 years). 1 Investigator-assessed etiologies of nocturia included nocturnal polyuria, overactive bladder, benign prostatic hypertrophy, global polyuria, and unknown causes. The trial arms were well-matched for these etiologies and for demographic and clinical characteristics. Key exclusion criteria included nocturnal enuresis, diabetes insipidus, unstable diabetes mellitus, obstructive sleep apnea, New York Heart Association class 2 to 4 congestive heart failure, a documented history of polydipsia, uncontrolled hypertension (systolic pressure >165 mm Hg and diastolic pressure >100 mm Hg), unstable angina, syndrome of inappropriate antidiuretic hormone secretion (SIADH), severe daytime lower urinary tract symptoms with more than 8 daytime voids per day, prior treatment with desmopressin for nocturia, and illness requiring systemic corticosteroid therapy. Concomitant medications for benign prostatic hypertrophy and overactive bladder were permitted if patients had been on stable doses for the past 6 months and did not change these doses during the study.

NOCTIVA Met Endpoints in Phase 3 Trials

Both doses of NOCTIVA achieved statistical significance for the two co-primary endpoints in a pooled analysis of data from both trials. 1 On average, nocturic voids decreased by 1.5 episodes with NOCTIVIA 1.66 mcg and by 1.4 episodes with NOCTIVA 0.83 mcg, versus a reduction of 1.2 episodes with placebo (each P<0.0001). Results were similar in each individual trial. In the pooled analysis, the percentage of patients who experienced at least a 50% reduction in mean nocturic episodes per night was 48.7% in the 1.66-mcg group and 37.9% in the 0.83-mcg group versus 30.3% in the placebo group (P<.0001 and P=.0055, respectively). NOCTIVA 1.66 mcg showed a statistically significant effect for this co-primary endpoint in each individual trial, whereas NOCTIVA 0.83 mcg showed a statistically significant effect only in the pooled analysis.

Both doses of NOCTIVA also significantly reduced nocturnal urine production compared with placebo. In the pooled analysis, nocturnal urine volume at baseline was approximately 805 mL in all three pooled treatment groups. At week 12, mean reductions in nocturnal urine volume were 259.7 mL in the pooled 1.66-mcg group and 195.2 mL in the 0.83-mcg group versus 132.7 mL in the placebo group (P<.0001 and P=.0025, respectively). Results were similar in the individual trials.

As we have discussed, waking during the first 3 to 4 hours of sleep interrupts restorative sleep, leading to next-day fatigue, discomfort, and a decreased pain threshold.14 NOCTIVA significantly increased first uninterrupted sleep periods in the pooled analysis of data from both  trials. Mean increases were 108 minutes in the 1.66-mcg group and 96 minutes in the 0.83-mcg group versus 72 minutes in the placebo group (each P<.0001). 1 By the end of treatment week 12, first uninterrupted sleep periods averaged 252 minutes (i.e., 4.2 hours) in the 1.66-mcg group and 240 minutes (4.0 hours) in the 0.83-mcg group, versus 210 minutes (3.5 hours) in the placebo group (each P<.0001).10

Compared with placebo, NOCTIVA also significantly increased the percentage of nights in which patients had either no nocturia or a single nocturic episode. 1 These percentages were 46.6% in the 1.66-mcg group and 39.9% in the 0.83-mcg group versus 33.8% in the placebo group in the pooled analysis (P<.0001 and P=.012, respectively). NOCTIVA 1.66 mcg produced a statistically significant effect for this secondary endpoint in each trial, whereas NOCTIVA 0.83 mcg reached statistical significance in the pooled analysis but not in the individual trials. In the pooled analysis, the percentages of nights with no nocturic episodes were 10.9% with NOCTIVA 1.66 mcg and 8.2% with NOCTIVA 0.83 mcg versus 5.3% with placebo (P<.0001 and P=.020, respectively).

In summary, NOCTIVA 1.66 mcg and NOCTIVA 0.83 mcg met co-primary and secondary endpoints in the pooled analysis of data from both trials. NOCTIVA 1.66 mcg also met these endpoints in each of the two individual trials, despite a considerable placebo response. The reason for this placebo response remains unclear. Education regarding lifestyle modifications might have played a role, although patients were instructed not to alter their usual fluid intake .

NOCTIVA also shows durable efficacy. In addition to the double-blind trials, two phase 3, open-label studies evaluated NOCTIVA 0.83 mcg for up to 43 weeks and NOCTIVA 1.66 mcg for up to 126 weeks. In both studies, NOCTIVA reduced nocturic episodes by approximately two episodes per night from baseline, and this improvement persisted throughout follow-up.

Impact on Daily Life 

The higher 1.66-mcg dose of NOCTIVA was associated with significant improvements in patient-reported quality of life. 1 In the DB4 trial, NOCTIVA 1.66 mcg produced significant improvements from baseline in the overall INTU impact score (P=.0255) and in the nighttime domain score (P=.0118). Overall impact scores decreased by a mean of 14.1 points in the 1.66-mcg group, 12.4 points in the 0.83-mcg group, and 11.5 points in the placebo group. 1 Nighttime domain impact scores decreased by a mean of 18.0 points in the 1.66-mcg group, 16.0 points in the 0.83-mcg group, and 14.5 points in the placebo group. Differences in overall and nighttime impact scores between the 0.83-mcg group and the placebo group did not reach statistical significance.

Safety

NOCTIVA demonstrated an acceptable safety profile. Nasal discomfort and nasopharyngitis were the most common treatment-related adverse events in the two double-blind trials. These usually were mild to moderate in severity and affected similar proportions (2.6% to 5.6%) of individuals in the treatment and placebo arms. 1 The incidence of serious adverse events also was similar among arms (2% in the NOCTIVA 1.66 and 0.83 mcg groups and 3% in the placebo group). In the 1.66-mch arm, there was one case each of serious treatment-emergent hyponatremia and worsening hypertension that were considered probably related to treatment.

A total of 5.9% of patients in the pooled analysis discontinued treatment due to adverse effects, most commonly nasal symptoms such as congestion, rhinorrhea, sinus discomfort, and throat irritation. 1 Hyponatremia developed 6 days to 12 weeks after treatment initiation and affected similar proportions of men and women. The proportion of patients who developed serum sodium levels between 130 and 134 mmol/L was 11.2% in the 1.66-mcg group, 8.4% in the 0.83-mcg group, and 4.4% in the placebo group. The proportion of patients who developed serum sodium levels in the 126 to 129 mmol/L range was 2.0% in the 0.83-mcg and 1.66-mcg groups and 0% in the placebo group.

The incidence of moderate to severe  hyponatremia (serum sodium 125 mmol/L or less regardless of symptoms or less than 130 mmol/L with symptoms) was 1.1% in the 1.66-mcg group, 0% in the 0.83-mcg group, and 0.2% in the placebo group. 1 All five patients in the 1.66-mcg group who developed serum sodium levels of 125 mmol/L or less were older than 65 years, and four were receiving contraindicated medications (inhaled or systemic corticosteroids). 1 The only placebo patient who developed a serum sodium level less than 125 mmol/L also was older than 65 years. Nausea and vomiting consistent with hyponatremia affected one patient each in the 1.66-mcg and placebo groups.

NOCTIVA has not been compared with other formulations of desmopressin in head-to-head trials.10 However, it is noteworthy that even though the DB3 and DB4 trials did not impose fluid restrictions and 54.5% of participants were 65 years or older,1 the incidence of hyponatremia was generally less than that in studies of oral and orally disintegrating desmopressin formulations (3% to 16%).73 However, because NOCTIVA contains desmopressin, its prescribing label includes a boxed warning for hyponatremia.79 Clinicians should avoid prescribing NOCTIVA for patients at increased risk for severe hyponatremia and should ensure that serum sodium concentration is normal before starting or resuming NOCTIVA. The use of NOCTIVA during pregnancy is not recommended and NOCTIVA also should not be used for the treatment of primary nocturnal enuresis in children, as the clinical  trials excluded these populations.

Case Study and Clinical Takeaways 

As discussed previously, 61-year-old Michael typifies the experience of nocturnal polyuria in many older men. However, women and younger patients also commonly experience bothersome, clinically significant nocturia. The mental and physical impact of nocturia can especially difficult for younger patients, who often juggle demanding work schedules and parenting or caregiving responsibilities.43,26

For example, Lisa is a 46-year-old flight attendant with a 5-year history of overactive bladder. She reports that antimuscarinic treatment with solifenacin (started at 5 mg and subsequently increased to 10 mg) has greatly improved her daytime urgency but not her nocturia. She continues to wake every 2 to 2.5 hours at night to void despite drinking only 32 ounces of water per day, avoiding all fluids after 6 PM, limiting caffeine to a single cup of coffee in the morning, and abstaining from alcohol. Lisa also states that her nocturia is causing significant daytime fatigue and difficulty functioning at work. She asks about intranasal desmopressin treatment with NOCTIVA.

Lisa appears to be a good candidate for NOCTIVA therapy. Her fluid intake and voiding patterns indicate that her nocturia is due to nocturnal polyuria, and she has no contraindications for receiving NOCTIVA such as current hyponatremia, a history of hyponatremia, or pregnancy, urinary retention, estimated glomerular filtration rate [GFR] below 50 mL/min/1.73 m2, polydipsia, primary nocturnal enuresis, syndrome of inappropriate antidiuretic hormone secretion [SIADH], New York Heart Association (NYHA) Class II-IV congestive heart failure, uncontrolled hypertension, or concomitant use of loop diuretics or systemic or inhaled glucocorticoids.79

NOCTIVA is available in two microdose formulations: 1.66 mcg for patients younger than 65 years who are not at increased risk for hyponatremia, and NOCTIVA 0.83 mcg for patients who are 65 years of age or older or for younger patients at increased risk for hyponatremia.79 After at least 7 days of treatment, the 0.83-mcg dose can be increased to 1.66 mcg if needed, provided that the serum sodium concentration stays within normal range during treatment with the 0.83-mcg dose.

Based Lisa’s age, history, and nocturia, she and her urologist decide to start NOCTIVA 1.66 mcg. Her serum sodium level is confirmed to be within normal range (141 meq/L) at baseline and she makes an appointment to have it re-measured 7 days and again 1 month after starting NOCTIVA.79 If her serum sodium remains within normal limits, she can continue NOCTIVA 1.66 mcg as long as she agrees to periodic serum sodium monitoring.

Periodic serum sodium monitoring should be performed more frequently in patients who are 65 years of age and older or at increased risk for hyponatremia. These include patients who are on medications that can increase the risk for hyponatremia, including selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, chlorpromazine, opiate analgesics, anti-inflammatory medications, lamotrigine, and carbamapezine. 76,77,79

Since Lisa is receiving the SSRI sertraline, her urologist advises repeat serum sodium monitoring every 6 months. She also is instructed to have her serum sodium level measured 7 days and 1 month after any increase in her antidepressant dose or if she adds or switches to other medications that can cause hyponatremia. She is given a list of these medications to take home along with a print-out summarizing her treatment instructions.

Lisa’s urologist informs her that her bottle of NOCTIVA contain 30 days of medication when used once per night, can be stored at room temperature for up to 60 days after opening, and does not need to be re-primed unless she goes more than 3 nights without using it.79 She is instructed to spray NOCTIVA once in each nostril 30 minutes before bedtime and not to double-dose, even if it seems that not much liquid is dispensed when the applicator is pumped.79

Finally, Lisa is educated to stop using NOCTIVA if she develops a condition that could increase its intranasal absorption, such as respiratory infections or hay fever, or if she develops any condition that might lead to fluid or electrolyte imbalances, such as illnesses that cause vomiting. She should only re-start NOCTIVA after such conditions fully resolve. Lisa returns after 1 month of treatment. Her serum sodium remains within normal limits (137 mEq/L) and she reports that she is now able to sleep 4 hours before waking to void. She reports significant improvements in her mood, energy levels, and productivity.

Summary

Nocturia, the most prevalent lower urinary tract symptom among adults of all ages, significantly reduces energy levels, productivity, and quality of life, increases the risk of serious somatic and mental illnesses, and is an independent risk factor for falls, fractures, and mortality. Although nocturnal polyuria is the most common cause of nocturia, the condition is complex and multifactorial and all possible etiologies must be considered to maximize the chances of treatment efficacy. Management should include lifestyle and behavioral modifications, although these can be difficult to sustain and usually are not effective by themselves.

Medications for overactive bladder and benign prostatic hypertrophy are not approved for the treatment of nocturnal polyuria and are usually ineffective in this context. NOCTIVA, a novel formulation of intranasal desmopressin, is the first FDA-approved treatment for adults with nocturnal polyuria who wake at least twice per night to void. In two randomized, double-blind, placebo-controlled trials, NOCTIVA significantly reduced mean nocturic episodes, increased the likelihood of achieving at least a 50% reduction from baseline in mean nocturic episode, significantly reduced nocturnal urine production, increased the percentage of nights in which patients had one or fewer nocturic episodes, and significantly increased the mean first uninterrupted sleep period. NOCTIVA 1.66 mcg also was associated with significant positive patient-reported improvements of quality of life based on a validated survey tool.

NOCTIVA showed a tolerable safety profile, with only 1.1% of treated patients in the safety analysis developing serum sodium levels of 125 mmoL per L or less. All these patients were older than 65 years, and two were receiving contraindicated medications in the form of inhaled or systemic corticosteroids. The safe, effective use of NOCTIVA requires appropriate patient selection, education, and monitoring of treatment response. NOCTIVA is available in two desmopressin microdoses (1.66 mcg and 0.83 mcg), enabling physicians to tailor therapy accordingly.

Published Date: April 16th, 2019
Written by: Roger R. Dmochowski, MD, MMHC, FACS and Benjamin M. Brucker, MD
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  11. Daily Med. LABEL: DESMOPRESSIN ACETATE- desmopressin acetate tablet https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=43bd65ca-0b1c-42c9-bbcd-7a97d3287581Accessed October 24, 2018.

Beyond First-line Treatment of Metastatic Castrate-resistant Prostate Cancer

In the previous review article (“First-line treatment of metastatic castrate-resistant prostate cancer”), metastatic castrate-resistant prostate cancer (mCRPC) and its approved first-line treatment options were elaborated. Unfortunately, all mCRPC patients will eventually progress despite evidence-based first-line treatments that patients receive. Therefore, an appropriate treatment strategy must be formalized. The working group of the Prostate Cancer Radiographic Assessments for Detection of Advanced Recurrence II (RADAR II) study attempted to offer recommendations on identifying disease progression, treatment management strategies, and suggestions on timing of initiating and discontinuing specific (CRPC) treatments.1 They recommended a layering approach comprised of approved therapies with unique or complementary mechanisms of action.1 According to this working group 12 Phase III studies evaluating combinations, layering, or sequencing of these agents are required to help improve clinical outcomes in the castrate clinical state. Following first-line treatment options for mCRPC patients, only second-line treatments given after treatment with docetaxel have been extensively assessed and these are detailed below.

Second-line treatment options for metastatic castrate-resistant prostate cancer

Cabazitaxel

Cabazitaxel is a new taxane drug with activity in docetaxel-resistant cancers. In the TROPIC study, a Phase III prospective randomized trial, cabazitaxel plus prednisone was compared to mitoxantrone plus prednisone in 755 mCRPC patients, who progressed after or during treatment with docetaxel2 (Figure 1). Patients received a maximum of ten cycles of cabazitaxel or mitoxantrone plus prednisone. Overall survival (OS) was the primary end-point, being significantly longer in cabazitaxel-treated patients (median: 15.1 vs. 12.7 months p < 0.0001). Progression-free survival (PFS) was significantly improved as well (median: 2.8 vs. 1.4 months, p < 0.0001), and prostate-specific antigen (PSA) response rate was also better (39.2% vs. 17.8%, p < 0.0002). Grade 3-4 adverse events developed more significantly in patients taking cabazitaxel, particularly hematological adverse effects (68.2% vs. 47.3%, p < 0.0002).3 Therefore, cabazitaxel should be given with prophylactic granulocyte colony-stimulating factor and needs to be administered by physicians with expertise in handling neutropenia and sepsis.4 When compared to docetaxel in the first-line setting, cabazitaxel was not shown to be superior.5


figure 1 TROPIC design

Figure 1. TROPIC study design

Abiraterone following docetaxel

The COU-AA-301 was a large Phase III randomized trial with a total of 1,195 mCRPC patients being randomised in a 2:1 ratio to abiraterone acetate plus prednisone or placebo plus prednisone (Figure 2). Abiraterone is an antiandrogen agent which inhibits the 17α-hydroxylase/C17,20-lyase (CYP17) enzyme. Initial positive results of this trial were reported after a median follow-up of 12.8 months6 and confirmed by the final analysis.7 All patients in this trial failed at least one chemotherapy regimen, which included docetaxel. The primary end-point was OS, and in the final analysis, after a median follow-up of 20.2 months there was a clear advantage to the abiraterone arm (median survival of 15.8 vs.11.2 months, HR: 0.74, p < 0.0001). The benefit for abiraterone remained in all secondary endpoints as well (PSA, radiologic tissue response, time to PSA or objective progression). No significant difference between the treatment arms was seen in the rate of grade 3-4 adverse events, aside from a higher rate of mineralocorticoid-related side-effects (mainly grade 1-2 fluid retention, edema, and hypokalaemia).7

figure 2 COU AA 301

Figure 2. COU-AA-301 study design

Enzalutamide after docetaxel

The AFFIRM trial randomized 1,199 mCRPC patients in a 2:1 fashion to enzalutamide, a nonsteroidal antiandrogen, or placebo (Figure 3). All accrued patients had progressed after docetaxel treatment.8 The planned interim analysis of the AFFIRM study was published in 2012 and after a median follow-up of 14.4 months, a clear benefit was shown for the enzalutamide-treated patients (median survival of 18.4 vs. 13.6 months, HR: 0.63, p < 0.001).8 This led to the recommendation to halt and unblind the study. Importantly, the observed benefit occurred irrespective of age, baseline pain intensity, and type of progression. Enzalutamide was also beneficial in patients with visceral metastases. The final analysis with longer follow-up had confirmed the OS results despite the crossover and extensive post-progression therapies. Enzalutamide also conferred a clear advantage in all the secondary endpoints (PSA, soft tissue response, quality of life, time to PSA or objective progression).8 No significant difference in the rate of side-effects was observed in the two groups, with a lower incidence of grade 3-4 adverse events in the enzalutamide arm. Importantly, enzalutamide-treated patients had a 0.6% incidence of seizures compared to none in the placebo arm.8


figure 3 AFFIRM trial
Figure 3. AFFIRM trial design

Apalutamide
Radium-223

Radium-223 is a targeted alpha therapy and is the only bone-specific drug that has been associated with a survival benefit in the mCRPC space. The ALSYMPCA trial was a large Phase III trial accruing 921 symptomatic mCRPC patients, who failed or were unfit for docetaxel chemotherapy.13 In this trial, patients were randomized to six injections of radium-223 or placebo, plus standard of care in both arms (Figure 4). The primary end-point was OS, and radium-223 significantly improved median OS by 3.6 months (HR: 0.70, p < 0.001).13 Radium-223 also conferred prolonged time to first skeletal event, improvement in pain scores and quality of life.13 No significant difference was noted in the rate of adverse effects between the treatment arms, aside from slightly more haematologic toxicity and diarrhea with radium-223.13 Whether patients were pretreated with docetaxel did not affect the benefit and safety of radium-223.14 Due to safety concerns, the label of radium-223 was restricted to use after docetaxel and at least one AR targeted agent.15 Importantly, the ERA-223 study assessed the effectiveness of early use of radium-223 together with abiraterone acetate and prednisolone (Figure 5). Unfortunately, this trial showed significant safety risks, especially with fractures and more deaths. Therefore, this combination is currently not recommended. These safety risks were more significant in patients without the concurrent use of antiresorptive agents.16


figure 4 ALSYMPCA trial

Figure 4. ALSYMPCA trial design



figure 5 EERA 223 trial
Figure 5. ERA 223 study design

Third line treatment following treatment with docetaxel and one hormonal treatment for metastatic castrate-resistant prostate cancer


Currently, there are no clear guidelines or recommendations regarding which treatment option is appropriate in this setting and this is open for debate. The choice for further treatment after docetaxel and one line of hormonal treatment for mCRPC is unclear.17 The available options include radium-223 or second-line chemotherapy (cabazitaxel). In unselected patients, subsequent treatments are expected to have a lower benefit than with earlier use18. There is also evidence that cross-resistance between enzalutamide and abiraterone exists.19, 20 There is a unique subset of patients worth mentioning with tumors demonstrating homozygous deletions or deleterious mutations in DNA-repair genes. In these patients Poly(ADP-ribose) polymerase (PARP) inhibitors have been reported to confer high rates of response. Therefore, patients who were previously treated with docetaxel and at least one novel hormonal agent; and whose tumors demonstrated homozygous deletions or deleterious mutations in DNA-repair genes showed an 88% response rate to Olaparib, a PAPR inhibitor.21 This represents an example of how treatment can be tailored according to the tumor mutation profile.22 In a randomized Phase II study of mCRPC patients, olaparib combined with abiraterone was compared to placebo and abiraterone. This study demonstrated a clinical benefit in olaparib-treated patients, regardless if mutations in DNA-repair genes existed.23 However, this combination treatment was shown to be toxic with significant side effects reported in 34% of patients vs. only 18% in the placebo arm.23 

For patients with mismatch repair deficiency, the PD-1 inhibitor pembrolizumab was approved by the FDA for all tumors, including PCa. More specifically, pembrolizumab demonstrated antitumor activity and disease control with acceptable safety in RECIST-measurable and bone-predominant mCRPC, which was previously treated with docetaxel and novel AR antagonists.24 

In the COMET-1 trial 1028 patients with progressive mCRPC after treatment with docetaxel and abiraterone and/or enzalutamide were randomly assigned at a 2:1 ratio to either cabozantinib 60 mg, a tyrosine kinase inhibitor, or prednisone 5 mg twice per day.25 The primary endpoint was OS, and the secondary endpoint included bone scan response after 12 weeks of treatment. Additional exploratory analyses included radiographic PFS (rPFS) and effects on circulating tumor cells, bone biomarkers, serum PSA, and symptomatic skeletal events.25 This trial demonstrated that cabozantinib did not significantly improve OS compared with prednisone in heavily pre-treated mCRPC patients (median OS was 11.0 months with cabozantinib and 9.8 months with prednisone, HR 0.90; 95% CI, 0.76 to 1.06; stratified log-rank P = 0.213).25 Cabozantinib had some activity in improving bone scan response, rPFS, symptomatic skeletal events, and bone biomarkers but not PSA outcomes.25

Changing and sequencing treatment in metastatic castrate-resistant prostate cancer


There are several open questions and dilemmas regarding when to change treatment in mCRPC patients and what is the most appropriate treatment sequence.

The appropriate time to change treatment in mCRPC patients is not entirely clear. No controversy exists regarding the need to change treatment when patients have symptomatic progression of their metastatic disease. Despite the many available treatment options to date, no head to head comparison has been made publicly available, while data assessing the correct sequence of treatment is being assessed. As data are lacking, physicians have been using the ECOG performance score to stratify patients before deciding on the “appropriate” treatment plan. Men with a good performance status are likely to tolerate more treatments as opposed to men with lower performance scores.

The National Comprehensive Cancer Network (NCCN) considers the onset of visceral disease to be a detrimental factor. Patients with liver metastases have especially poor outcomes for as of yet an unknown reason. In a meta-analysis including over 8,000 mCRPC patients who were enrolled in Phase III trials, patients with lymph-node- only disease appeared to have the best OS (median, 31.6 months; 95% CI, 27.9 to 36.6 months), with patients with lung and bone metastases having shorter and similar median OS (19.4 months [95% CI, 17.8 to 20.7 months] vs. 21.3 months [20.8 to 21.9], respectively), and patients with liver metastases demonstrating the worst OS (median, 13.5 months; 95% CI, 12.7 to 14.4 months).26 Therefore, the type of metastases the patient has can be used as a guide to when and how aggressive the treatment strategy should be.

Abiraterone and enzalutamide are highly active agents harboring a substantial effect on PFS, with trials comparing monotherapy with prednisone or placebo.27, 28 However, a subset of patients will not respond to these drugs. A patient who does not respond well will require a change of treatment. It is therefore important to see these patients frequently once starting therapy and assess their response. If no PSA decline is witnessed, the treatment needs to be changed.

When considering the appropriate treatment sequence in mCRPC, there are no clear guidelines or recommendations to date, and our limited knowledge is based mainly on retrospective data. In one non-randomized retrospective study, PFS, OS, and PSA responses from consecutive patients with chemotherapy-naïve mCRPC were compared between those who received abiraterone followed by enzalutamide and those who received enzalutamide followed by abiraterone.29 Initially, a slight improvement in patients who started with abiraterone and transitioned to enzalutamide was seen with improved PFS. An expanded retrospective study confirmed the general trend, showing that patients who started with abiraterone and then transitioned to enzalutamide had better PFS (median, 455 days [95% CI, 385 to 495 days]) than patients who started with enzalutamide and transitioned to abiraterone (median, 296 days; 95% CI, 235 to 358 days).30 However, OS was not significantly different between the groups.30 Furthermore, the authors of an ongoing randomized Phase II study comparing abiraterone vs. enzalutamide in patients with treatment-naïve mCRCP reported their interim results.31 After a median follow-up of 22.3 months, a PSA decline of more than 50% occurred in 34% of abiraterone treated patients compared to 4% in the enzalutamide treated patients (p<0.001).31 Additionally, the median time to PSA progression on 2nd-line therapy was 2.7 vs 1.3 months (HR 0.38, 95% CI 0.26-0.56) in favor of abiraterone.31 Lastly, the median OS was not reached vs 24.3 months (HR 0.82, 95% CI 0.53-1.27) in favor of abiraterone.31 As data regarding appropriate treatment sequencing is still being collected and analyzed, many physicians currently base their decision on which medication to start according to the adverse effects that we want to avoid. Abiraterone is commonly associated with edema, and therefore should be avoided in men with congestive heart failure,27 while enzalutamide is more likely to cause central nervous system toxicity and should probably be avoided in older patients.32 

Radioligand therapy for metastatic castrate-resistant prostate cancer patients


PSMA-PET/CT imaging has significantly become more common in recent years. This has led to the emergence of a new field of radioligand directed therapy among heavily pretreated mCRPC patients. PCa metastases express PSMA, making it a promising approach to developing new tracers for targeted radionuclide therapies. PSMA is a non-secreted type II transmembrane protein produced almost exclusively by prostatic tissue and on tumor-associated neovasculature.33 Unlike other biomarkers, such as PSA, which may decrease with increasing neoplastic de-differentiation, PSMA has been shown to be upregulated in high-grade, de-differentiated PCa.34 

Since 2015, several institutional studies have reported promising response rates and a favorable safety profile for radioligand therapy with 177Lu-PSMA-617 in mCRPC patients.35-37 However, these studies had small sample sizes and questionable generalizability. To addresses these limitations, a large multicenter German analysis assessed a cohort of patients treated with 177Lu-PSMA-617.38 This study included 145 mCRPC patients treated with 177Lu-PSMA-617 at 12 centers undergoing 1-4 therapy cycles. The study reported an overall biochemical response rate of 45% after all therapy cycles, with 40% of patients responding after a single cycle. Notably, negative predictors of the biochemical response included elevated alkaline phosphatase and the presence of visceral metastases.38

In a large meta-analysis published in 2017, 10 studies were assessed including 369 patients. This meta-analysis assessed the safety and efficacy of 177-Lutetium in mCRPC patients.39 The pooled proportion of patients with any PSA decline was 68% (95% CI: 61–74%); and the pooled proportion of patients with 450% PSA decline was 37% (95% CI: 22–52).39 This meta-analysis suggested promising early results for the treatment of mCRPC patients, especially in patients treated with the more recently developed radioligands, with approximately two-thirds of them showing a biochemical response.39 

Although 177Lu-PSMA-617 is the most well-studied radioligand to date, there are additional compounds in development and undergoing initial testing. These include 177Lu-J591, 90Y-J591, 131I-MIP 1095, 177Lu-PSMA-I&T, and 225Ac-PSMA-617.40

Treatment and prevention of skeletal-related events


Patients with mCRPC commonly endure painful bone metastases with external beam radiotherapy (EBRT) being a highly effective treatment.41 Possible complications due to bone metastases include vertebral collapse or deformity, pathological fractures, and spinal cord compression. Cementation can be an effective treatment for a painful spinal fracture, clearly improving both pain and quality of life.42 However, standard palliative surgery can still be offered for managing osteoblastic metastases.43 Impending spinal cord compression is an emergency event that must be recognized as soon as possible. Patients should be educated to recognize the warning signs. If this is suspected, high-dose corticosteroids must be given and an MRI is required. A neurosurgeon or orthopedic surgeon consultation needs to be planned to discuss a possible decompression, followed by EBRT.44

Zoledronic acid, a bisphosphonate, has been evaluated in mCRPC patients in an attempt to reduce skeletal-related events (SRE). 643 mCRPC patients with bone metastases were randomized to receive zoledronic acid, 4 or 8 mg every three weeks for fifteen consecutive months, or placebo.45 The 8 mg dose was poorly tolerated without showing a significant benefit. However, at 15 and 24 months of follow-up, the 4 mg dose conferred fewer SREs compared to the placebo group (44 vs. 33%, p = 0.021), and less pathological fractures (13.1 vs. 22.1%, p = 0.015). Additionally, the time to first SRE was longer in the zoledronic acid group. However, no survival benefit was seen in any prospective trial assessing bisphosphonates.

Denosumab is a fully human monoclonal antibody directed against RANKL (receptor activator of nuclear factor kappa-B ligand). It is a key mediator of osteoclast formation, function, and survival. In non-metastatic CRPC, denosumab has been associated with increased bone-metastasis-free survival compared to placebo (median benefit: 4.2 months, HR: 0.85, p = 0.028).44 Like zoledronic acid, this benefit did not translate into a survival difference and neither the FDA or the EMA had approved denosumab for this indication.46 A Phase III trial compared the efficacy and safety of denosumab (n = 950) with zoledronic acid (n = 951) in mCRPC patients. Denosumab was shown to be superior to zoledronic acid in delaying or preventing SREs, as shown by time to first SRE (pathological fracture, radiation or surgery to bone, or spinal cord compression) of 20.7 vs. 17.1 months, respectively (HR: 0.82, p = 0.008). However, these findings were not associated with any survival benefit, and in a recent post-hoc re-evaluation of end-points, denosumab had actually shown an identical rate of SREs to zoledronic acid.47 It is critical to remember that these medications are associated with substantial toxicity, of 5% and 8.2% in non-metastatic CRPC and mCRPC, respectively.47, 48 All patients are required to be examined by a dentist prior to initiating this therapy, as the risk of jaw necrosis is increased by several risk factors including a history of trauma, dental surgery or dental infection.49 and the number of years the medication is used.

Recently, the randomized, double-blind Phase III trial (COMET-2; NCT01522443) was published, comparing cabozantinib, to mitoxantrone + prednisone in mCRPC patients with narcotic-dependent pain from bone metastases.50 All patients had progressed after treatment with docetaxel and either abiraterone or enzalutamide.50 The primary endpoint was pain response at week 6 and confirmed again at week 12. Enrollment was terminated early because cabozantinib did not demonstrate any survival benefit in mCRPC patients in the companion COMET-1 trial,25 described earlier. At study closure of the COMET-2 trial, only 119 patients were randomized. The trial demonstrated no significant difference in the pain response with cabozantinib versus mitoxantrone-prednisone.50

Future and ongoing trials


There are currently 24 registered ongoing Phase III trials involving mCRPC patients.

Some studies worth mentioning with much-anticipated results include the following:

  1. The combination of abiraterone and Olaparib as first-line therapy in mCRPC patients (NCT03732820)
  2. A study assessing the role of Rucaparib (a PARP inhibitor) vs. physician’s choice therapy in mCRPC patients (TRITON3 trial - NCT02975934)
  3. The combination of pembrolizumab with various other medications including enzalutamide (NCT03834493 - as part of the MK-3475-641/KEYNOTE-641 trial), docetaxel (NCT03834506 - as part of the MK-3475-921/KEYNOTE-921 trial), and olaparib (NCT03834519 – as part of the MK-7339-010/KEYLYNK-010)
  4. The ACIS trial, which will assess the combination of apalutamide, and abiraterone + prednisone in mCRPC patients (NCT02257736)
  5. A study assessing Masitinib (a tyrosine kinase inhibitor) plus docetaxel (NCT03761225)
  6. The combination of Talazoparib (a PARP inhibitor) + plus enzalutamide (NCT03395197),
  7. The combination of Atezolizumab (an anti-PD-L1 monoclonal antibody) + enzalutamide (NCT03016312)
  8. The combination of docetaxel and Radium-223 (NCT03574571)
  9. A study assessing 177Lu-PSMA-617 in mCRPC patients (NCT03511664)
  10. The IPATential150 trial – assessing the combination of Ipatasertib (an orally administered, ATP-competitive, selective AKT inhibitor) plus abiraterone (NCT03072238)

Conclusions


Substantial progress has been made in the mCRPC space in the last several years. Optimal management of mCRPC patients is a growing challenge as more potential treatments are added to the armamentarium. Choosing the right treatment for the right patient, and the correct sequence and combination of the increasing number of available medications will be the main challenge in the years to come. We currently lack level one evidence regarding the proper sequence and/or combination of current available medications, and physicians are faced with making these decisions without supporting data. Patients will most likely benefit from unique medications with complementary mechanisms of action in order to avoid cross-resistance. An important unmet clinical need thus far consists of acquiring evidence about the efficacy, safety, and tolerability of combination regimens, and optimized approaches for identifying patients most suited for specific treatments.

Published Date: November 19th, 2019
Written by: Hanan Goldberg, MD
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Prostate Cancer and Tumor Markers

The discovery of prostate-specific antigen (PSA) in the late 1970s and its widespread application and adoption in the 1980s and 1990s ushered in the prostate cancer screening and disease monitoring era. As the first tumor marker for prostate cancer, it is organ specific but not cancer specific.1 thus providing the opportunity for further tumor marker investigation. A potential biomarker must go through a rigorous vetting process from discovery → differentiation of case from control → ability to detect preclinical disease (defining a positive test) → indications for application and validation → cancer control studies.2 Secondary to the cost and time involved, biomarkers are rarely tested in large randomized controlled trials (RCTs). However, the development of the Prospective Randomized Open, Blinded Endpoint (PROBE) initiative for biomarker studies was designed to overcome spectrum and ascertainment bias and give guidance for validation studies.3 Biomarkers are typically evaluated based on their positive predictive value (probability that a positive test indicates the presence of disease) and negative predictive value (probability that a negative test indicates the absence of disease), entities that rely on the test’s specificity, sensitivity, and prevalence of the disease. This article will focus on briefly reviewing the clinical utility of several commonly used tumor markers associated with prostate cancer detection.

Blood

PSA
PSA is part of the kallikrein gene family located on chromosome 19 and functions as a serine protease, predominantly produced by prostate luminal cells. PSA in the serum is typically bound to proteins (~80% of PSA; complexed) or unbound (free PSA). The production of PSA is androgen dependent4 and in the absence of cancer varies with age,5 race,6, 7 and prostate volume.8 African-American men without prostate cancer have a higher PSA level compared to similar Caucasian men when assessed on a volume-to-volume ratio.9 Additionally, many studies have suggested that PSA in men with higher body mass index (BMI) have lower PSAs, a concept referred to as “hemodilution”:10 a greater plasma volume leading to lower hematocrit and PSA. Recent studies have provided further support for the hemodilution theory, in that only a fraction of lower PSA values in obese men are attributed to testosterone and dihydrotestosterone levels, with the remaining lower PSA explained presumably by hemodilution.11 The greatest contributor to elevated PSA is prostatic diseases, namely prostatitis, BPH and prostate cancer. Without question, the decrease in specificity associated with PSA and prostate cancer is an elevated PSA in men with prostatitis and/or BPH.

Free PSA (fPSA)
fPSA is PSA that is enzymatically inactive and non-complexed, making up 4-45% of total PSA;12 men with PSA from prostate cancer cells have a lower percentage of total PSA that is free, compared to those without prostate cancer.13 fPSA has FDA approval for men with a negative digital rectal examination (DRE) and total PSA level of 4-10 ng/mL, largely on the basis of a prospective study of men demonstrating a %fPSA (fPSA/total PSA) cutoff of 25% detecting 95% of prostate cancers, while avoiding 20% of biopsies.14 A generally acceptable cut-point ranges from 15-25%. Twenty years later, %fPSA is still used for clinically appropriate men, most commonly used in those with an elevated PSA and a negative prostate biopsy. In these men, studies have reported a 5% cancer under-detection rate and 21% cutoff for repeating prostate biopsy.15

Kallikreins
PSA, also known as human kallikrein 3 (hK3), is the most famous of the kallikreins, however, there are other kallikreins that have recently been explored as prostate cancer tumor markers. hK2 shares 80% amino acid homology with PSA, however, is weakly expressed in benign tissue and intensely expressed in prostate cancer tissue.16 Low-grade disease generally has low expression of hK2, whereas aggressive disease has high levels of expression.16 Recently, the hK2 kallikrein has been incorporated into a panel of kallikrein markers (total PSA, free PSA, intact PSA, and hK2, along with clinical information), commercially available as the 4KScore Test, used for calculating a patient’s percent risk for aggressive prostate cancer. First described in 2008, Vickers et al.17 tested the utility of the kallikrein panel in 740 men in the Swedish arm of the ERSPC screening trial. They found that adding free and intact PSA with hK2 to total PSA improved the clinical area under the curve (AUC) from 0.72 to 0.84. When the authors applied a 20% risk of prostate cancer as the threshold for biopsy, 424 (57%) of biopsies would have been avoided, missing 31 of 152 low-grade and 3 of 40 high-grade cancers.17 Since this study a decade ago, many studies have validated these findings, including among 6,129 men participating in the ProtecT study:18 the AUC for the four kallikreins was 0.719 (95%CI 0.704-0.734) vs 0.634 (95%CI 0.617-0.651, p<0.001) for PSA and age alone for any-grade cancer, and 0.820 (95%CI 0.802-0.838) vs 0.738 (95%CI 0.716-0.761) for high-grade prostate cancer. 

Prostate Health Index (phi)
The phi test combines total, free and [-2]proPSA into a single score for improving the accuracy of prostate cancer detection. In the seminal study leading to FDA approval, Catalona et al.19 assessed phi scores among 892 patients without prostate cancer and a PSA between 2-10 ng/mL. They found that an increasing phi score was associated with a 4.7-fold increased risk of prostate cancer and a 1.6-fold increased risk of Gleason score ≥ 4+3 disease at prostate biopsy. Furthermore, the phi score AUC exceeded that of %fPSA (0.72 vs 0.67) to discriminate high vs low-grade disease or negative biopsy. In a subsequent study, Loeb et al.20 confirmed the phi score’s ability to outperform total, free and [-2]proPSA for identifying clinically significant prostate cancer.

Urine

Prostate Cancer Antigen 3 (PCA3)
PCA3 is a long noncoding RNA shed into the urine that is not expressed outside the prostate and is associated with much higher expression in malignant than benign prostate tissue.21 Prior to collecting urine for a PCA3 test, a “rigorous” DRE is performed in order to enhance the sensitivity of the test. The commercial PCA3 score is reported as a ratio of urine PCA3 mRNA to urine PSA mRNA x 1000. The optimal cutoff is still debated, however in a contemporary comparative effectiveness review, Bradley et al.22 showed that a PCA3 threshold of 25 resulted in a sensitivity of 74% and specificity of 57% for a positive biopsy. This threshold led to FDA approval of the PCA3 test in 2012 among men with a prior negative prostate biopsy.

Since then, several groups have reported results of PCA3 in biopsy naïve men. In a retrospective review of 3,073 men undergoing initial biopsy, Chevli et al.23 found that the mean PCA3 was 27.2 for those without, and 52.5 for patients with prostate cancer. Prostate cancer was identified in 1,341 (43.6%) men; on multivariable analysis, PCA3 was associated with any (OR 3.0, 95%CI 2.5-3.6) and high-grade (OR 2.4, 95%CI 1.9-3.1) prostate cancer after adjusting for clinicopathologic variables. Furthermore, PCA3 outperformed PSA in the prediction of prostate cancer (AUC 0.697 vs 0.599, p<0.01) but did not for high-grade disease (AUC 0.682 vs 0.679, p=0.702).23

microRNAs (miRNAs)
miRNAs are small, noncoding single-stranded RNAs involved in the regulation of mRNA. Due to their short sequence (typically 19-22 nucleotides), miRNAs are highly stable in most body fluids (including urine) as they are resistant to RNase degradation.24 Several miRNAs have been implicated as potential biomarkers in prostate cancer diagnosis and management, including miRNA-141, miRNA-375, miRNA-221, miRNA-21, miRNA-182 and miRNA-187.25, 26 miR-187 detected in urine has been suggested as a candidate for improving the predictive value for a positive biopsy; a prediction model including serum PSA, urine PCA3, and miR-187 provided 88.6% sensitivity and 50% specificity (AUC 0.711, p = 0.001) for a positive biopsy.26 Ultimately, these miRNAs need to be further validated in terms of their ability to regulate various pathways important for prostate cancer management and their potential role as tumor markers.

Combining Tumor Markers

In an effort to improve the predictive accuracy of a positive biopsy, the last several years have seen a plethora of studies combining biomarkers to not only improve predictive accuracy above that offered by PSA, but also individual, newer biomarkers. As previously mentioned, the decrease in specificity associated with PSA and prostate cancer is secondary to an elevated PSA in men with prostatitis and/or BPH. The “perfect” biomarker (or combination) would delineate prostate cancer (and ultimately high-grade prostate cancer) from other benign entities.

Vedder et al.27 assessed the added value of %fPSA, PCA3, and 4KScore Test to the ERSPC prediction models among men in the Dutch arm of the ERSPC screening trial. Prostate cancer was detected in 119 of 708 men – adding %fPSA did not improve the predictive value of the risk calculators, however, the 4KScore discriminated better than PCA3 in univariate models (AUC 0.78 vs. 0.62; p=0.01). In the overall population, there was no statistically significant difference between the multivariable model with PCA3 (AUC 0.73) versus the model with the 4KScore (AUC 0.71; p=0.18). Among 127 men with a previous negative biopsy, Auprich et al.28 compared the performance of total PSA, %fPSA, PSA velocity (PSAV), and PCA3 at first, second and ≥ third repeat biopsy. At first repeat biopsy, PCA3 predicted prostate cancer best (AUC 0.80) compared with total PSA. A second repeat biopsy, %fPSA demonstrated the highest accuracy (AUC 0.82), and again at ≥ third repeat biopsy %fPSA demonstrated the highest accuracy (AUC 0.70).28 

This sampling of studies demonstrates that many combinations of biomarkers are being studied in an effort to improve detection of high-grade cancer and decrease the number of unnecessary biopsies. The next generation of biomarker combinations has and will continue to incorporate multi-parametric prostate MRI into predictive algorithms for clinically significant prostate cancer.29-31

Conclusions

For over four decades, research efforts have been directed towards improving the detection of prostate cancer and attempting to build on the predictive accuracy of the first prostate cancer tumor marker, PSA. With the United States Preventative Services Task Force’s 2012 recommendation for the urgent need to identify new screening efforts to better identify indolent versus aggressive disease, the last several years have seen a dramatic increase in prostate cancer biomarker options. As briefly highlighted, biomarker combinations studies have demonstrated improved predictive accuracy of positive biopsies; however, these combinations are far from perfect, are expensive and much work remains to be done. Furthermore, the specific indication (pre-biopsy, post-negative biopsy, active surveillance, etc) and a combination of tumor markers remain to be fully elucidated.

Published Date: April 16th, 2019
Written by: Zachary Klaassen, MD, MSc
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