Global Society of Rare GU Tumors 2020

GSRGT 2020: Conservative Therapy of Primary Penile Cancer

(Urotoday.com) The penile cancer session at the inaugural virtual summit of the Global Society of Rare Genitourinary Tumors (GSRGT) included a presentation of conservative therapy for primary penile cancer from Dr. Peter Johnstone from the Moffitt Cancer Center. Dr. Johnstone notes that there are important tenants of penile cancer therapy, including (i) centralization of care to high volume centers (penile cancer is not for the timid), (ii) multidisciplinary consultation (teamwork is essential), and (iii) enrolling patients in clinical trials whenever possible (patient selection is critical).


The gold standard for the management of primary invasive squamous cell carcinoma of the penis is radical/total penectomy with negative margins. However, there has been an increasing acceptance of less or non-invasive management based on stage and grade. These options include topical treatment, organ-sparing surgical approaches, and radiotherapy. One of the primary drivers of penile preserving treatment is to maintain sexual function for these patients. Sansalone and colleagues assessed sexual function and satisfaction among 25 patients undergoing partial penectomy from October 2011 thru November 2013, with a median follow-up of 14 months (range 12-25 months).1 Not surprisingly, they found that penile cancer leads to several sexual and psychosexual dysfunctions. However, patients who undergo partial penectomy for penile cancer can maintain the sexual outcomes at levels slightly lower to those that existed in the period before surgery.

Topical options for penile sparing therapy (particularly for patients with carcinoma in situ) include 5-fluorouracil and imiquimod. Penile preserving surgery has been shown across several studies to be oncologically safe, the ability to maintain function and well-being is technically feasible for a urologist, and can utilize techniques of skin grafting if necessary. In a multi-institutional study of 1,188 patients undergoing penile sparing surgery, Baumgarten et al found that over a median follow-up of 43.0 months there were 252 local recurrences (21.2%), of which 99 (39.3%) developed within the first year.2 Furthermore, median time to local recurrence was 16.3 months and the 5-year local recurrence-free survival incidence was 73.6%. When stratified by stage, the 5-year local recurrence-free survival rate was 75.0%, 71.4%, and 75.9% in Ta/Tis, T1, and T2 cases, respectively. Only margin status was significantly associated with local recurrence on multivariable analysis (p = 0.001).

Penile radiotherapy includes external beam radiotherapy and brachytherapy, specifically LDR, HDR, and surface mold (<3 mm thick) options. In a study from the Princess Margaret Cancer Centre in Toronto, McLean and colleagues treated 26 patients with invasive carcinoma of the penis and 11 patients with carcinoma in-situ.3 Radiation treatment was delivered to a dose ranging from 25 Gy in 10 fractions over 2 weeks to 60 Gy in 25 fractions over 5 weeks. The 5-year overall actuarial survival for patients with invasive cancers was 62% and the cause-specific survival was 69%, with control of the primary lesion successful in 61.5% of cases. Among patients with carcinoma in-situ, all achieved a complete response (follow-up 1 to 14 years).

Dr. Johnstone notes that penile brachytherapy is oncologically safe, particularly when the lesion is confined to the glans and is <4 cm in diameter. However, it is technically complex and requires a radiation oncologist with specific brachytherapy experience, in addition to a medical physicist. Although it does maintain function and well-being if indicated treatment of the inguinal lymph nodes still requires a surgical approach. As follows is the penile brachytherapy set-up:

GSRGT_penile_brachytherapy.png

Dr. Johnstone concluded his presentation by once again highlighting the importance of centralizing penile cancer care to high-volume hospitals, utilizing a multidisciplinary approach, and enrolling patients in clinical trials whenever possible.

Presented by: Peter Johnstone, MD, Vice Chair, Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL

Written by: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia Twitter: @zklaassen_md during the 1st Global Society of Rare Genitourinary Tumors Virtual Summit, December 11-12, 2020

References:

  1. Sansalone S, Silvani M, Leonardi R, et al. Sexual outcomes after partial penectomy for penile cancer: Results from a multi-institutional study. Asian J Androl. Jan-Feb 2017;19(1):57-61.
  2. Baumgarten A, Chipollini J, Yan S, et al. Penile sparing surgery for penile cancer; A multicenter international retrospective cohort. J Urol 2018 May;199(5):1233-1237.
  3. McLean M, Akl AM, Warde P, et al. The results of primary radiation therapy in the management of squamous cell carcinoma of the penis. Int J Radiat Oncol Biol Phys. 1993 Mar 15;25(4):623-628.
email news signup