(UroToday.com) During the annual American Urological Association (AUA) meeting in Chicago, Mr. Dennis Boynton and colleagues held a presentation on the impact of renal mass biopsy (RMB) for the management of renal tumors. Provided that RMB can aid in the diagnosis of such lesions, it is often used to determine the appropriate treatment modality, primarily in patients with tumors that are highly suspicious for malignancy. According to AUA Guidelines, RMB should be completed on a utility-based approach, especially when it may influence tumor management. Despite such stipulations, it is often underutilized as RMB is hindered by a lack of standardization and variation in practice between physicians and institutions. Therefore, Mr. Boynton et al. sought to explore the effect of RMB on active surveillance (AS), nephron-sparing intervention (NSI), and radical nephrectomy (RN) for cT1 renal masses (cT1RM). Considering that predominant literature prioritizes RMB in the treatment of T1a renal masses, Mr. Boynton further aimed to compare RMB usage between T1a and T1b tumors to understand how T1b may also be affected.
This study was completed using the Michigan Urological Surgery Improvement Collaborative (MUSIC-KIDNEY) database, a quality improvement initiative that prioritizes improving care for localized renal mass patients throughout the state of Michigan by improving renal biopsy utilization. The researchers retrospectively collected and analyzed data from 3,466 patients. This registry included individuals newly diagnosed with cT1RM managed with either AS, NSI (partial nephrectomy, tumor ablation, and stereotactic body radiation), or RN. Extracted data included: patient, tumor, RMB status, and management data.
Of this cohort, 626 (18%) received a RMB, with 17% having T1a and 20% with T1b pathology. There was no significant difference between T1a vs. T1b cohorts with or without RMB, or the patient populations with respect to age, race, sex, GFR> or ≤ 60, (Table 1).
Table 1. Reviews patient demographics in those that underwent RMB and no RMB.
Notably, management differed somewhat between cohorts with vs without RMB in AS (41% vs 50%), NSI (45% vs 35%), and RN (14% vs 15%) (p<0.001, Figure 1).
Figure 1. RMB is shown to greatly effect management strategy
For those with T1a masses with or without RMB, treatment rates included AS (44% vs 58%), NSI (48% vs 36%), and RN (7.8% vs 6.0%). On the otherhand, management of patients with T1b masses with or without RMB showed AS (33% vs 23%), NSI (37% vs 33%), and RN (30% vs 44%) (Figure 2).
Figure 2. RMB is shown to alter the management of T1a and T1b renal masses
Mr. Boynton announced that for every 8 biopsies that were obtained, 1 kidney is saved from a RN, within the T1b group. From this, moderator Dr. Ithaar Derweesh of UCSD noted “This is excellent work. I think you often see that the metric of ‘how many biopsies can save a patient from prostate cancer’…this is really the first time I have seen this within active surveillance literature.” This highlights the groundbreaking work that Mr. Boynton and colleagues have achieved, completing closer steps to the increased utilization of RMB, especially for T1b tumors.
Overall, Mr. Boynton et al. presented fascinating results that may spark a conversation to potentially impact the field or urologic oncology, by further impacting the utilization of RMB and avoiding invasive treatment modalities for benign masses. He concluded his presentation with these take-home messages:
- Patients with T1a masses that underwent RMB were more likely to purse invasive interventions compared to patients without a biopsy
- With RMB usage, utilization of more appropriate interventions, such as NSI and AS, were achieved for patients with T1b masses. In this group, every 8 RMB save 1 kidney from RN
- It is likely that patients with T1a masses feel pressured to pursue surgical treatment due to malignant pathology on RMB
- Obtaining a RMB may not be necessary in patients that are appropriate and willing to pursue AS
- Future directions may explore why there was a decrease in the use of AS in patients with T1a masses
Presented by: Dennis Boynton, Michigan State University, Corewell Health
Written by: Mariah Hernandez, Department of Urology, University of California, Irvine, @mariahch00 on Twitter during the 2023 American Urological Association (AUA) Annual Meeting, Chicago, IL, April 27 – May 1, 2023