MDACC 2018: Debate: Organ Preservation in Penile Cancer
Two modalities are typically employed for RT in penile cancer: external beam radiotherapy (EBRT) vs interstitial brachytherapy. Dr. Choi presented data showing that mean penile conservation rates after external beam radiation therapy approached 60-65%, with cancer-specific survivals between 80-85%. The modality is underutilized, however, due to challenges in consistent case-to-case reproductions of setting up the radiation field. Immobilization of the organ can be particularly challenging, although special devices can help with this. Adverse effects associated with EBRT include moist desquamation in the treated area, lengthy healing periods (up to 6 weeks), long-term pigment changes, telangiectasia, erectile dysfunction, urethral stenosis (1-15% of patients), and soft tissue necrosis (3%).
Interstitial brachytherapy has higher reported mean local control rates (close to 70-80%), but Dr. Choi noted that this was likely due to selection biases in published series. This approach is best suited for T1b or T2 disease, with tumors that are less than 4 cm in maximum diameter, and those confined to the glans with a prior circumcision. Among the adverse effects of interstitial brachytherapy for penile cancer include telangiectasia and hypopigmentation, meatal stenosis (8-25% incidence), and non-healing soft tissue ulceration (6-26%), with the risks varying depending on the dose, technique, and tumor volume.
The Case for Surgery
Dr. Curtis Pettaway made the counter-argument in favor of surgery to maximize organ preservation in penile cancer, noting that surgery provides rapid, effective tumor control, while concurrently providing important pathologic staging information to adequately assess the risk of inguinal metastasis. Whereas patients undergoing RT typically undergo a local biopsy, the more extensive lymph node dissections that surgery confers allows for more detailed risk stratification. Penile preserving surgery is standard and widely available, and Dr. Pettaway noted that with attention to detail, penile length and sexual function can be preserved.
Most penile tumors occur distally, with 90% of cases occurring in either the glans or preputial skin. The optimal tumors for organ preservation include Tis, Ta and T1 grade 1-2 tumors, where it is relatively easy to obtain local control and metastatic rates are between 0-10%. These tumors can be amenable to glans resurfacing, laser ablation, or excision with local reconstruction1. Surgery can also be considered in select distal T2 tumors that are low grade; these may be amenable to either glans sparing excisions, or glansectomy with reconstruction. Dr. Pettaway noted that organ-sparing surgery is widely utilized, margin distance is not necessarily predictive of relapse, and local recurrence was not predictive of survival. Importantly, glans preservation contributes to post-op restoration of male sexual function.2
Take-home messages: EBRT and interstitial brachytherapy are options for organ preservation with good local control rates, particularly for cases at low T stages. Meatal stenosis and soft tissue necrosis are more common after interstitial brachytherapy. Surgery can maximize organ preservation and offers the added benefit of complete excision, allowing for optimal staging information to assess the risk of inguinal metastasis. Surgery is standard, widely available, and offers low complication rates, including preservation of quality of life in early data.
Presented By: Seungtaek Choi, MD, and Curtis A. Pettaway, MD, University of Texas MD Anderson Cancer Center, Houston, Texas
References:
1. O’Kelly F, Lonergan P, Lundon D, Nason G, Sweeney P, Cullen I, et al. A Prospective Study of Total Glans Resurfacing for Localized Penile Cancer to Maximize Oncologic and Functional Outcomes in a Tertiary Referral Network. J Urol [Internet]. 2017 May;197(5):1258-63.
2. Yang J, Chen J, Wu X, Song N, Xu X, Li Q, et al. Glans preservation contributes to postoperative restoration of male sexual function: a multicenter clinical study of glans preserving surgery. J Urol [Internet]. 2014 Nov;192(5):1410–7.
Written by Dr. Vikram M. Narayan (@VikramNarayan), Urologic Oncology Fellow and Ashish M. Kamat, MD (@UroDocAsh), Professor, Department of Urology, Division of Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX at the 13th Update on the Management of Genitourinary Malignancies, The University of Texas (MDACC - MD Anderson Cancer Center) November 9-10, 2018, Dan L. Duncan Building, Houston, TX