Penile SCC is a rare malignancy that represents between 0.4% and 0.6% of all malignant tumors in the United States and occurs most commonly in men aged 50 to 70 years.4 The incidence is higher in developing countries, approaching 10% of malignancies in men. It occurs most commonly on the glans penis, prepuce, and coronal sulcus, and has multiple possible appearances, including erythematous and indurated, warty and exophytic, or flat and ulcerated lesions.5 Some reports indicate that more than 40% of penile SCCs are attributable to human papilloma virus,6 while lack of circumcision, chronic inflammation, poor hygiene, balanitis xerotica obliterans, penile trauma, human immunodeficiency virus, UVA treatment of penile psoriasis, and tobacco use are known risk factors.5
Invasive penile SCC generally is treated with penectomy (partial or total), radiation therapy, or MMS; SCC in situ can be treated with topical chemotherapy, laser therapy, and wide local excision (2-cm margins) including circumcision, complete glansectomy, or MMS.5 Squamous cell carcinoma in situ with urethral involvement treated with nonsurgical therapies is associated with higher recurrence rates, ultimately necessitating more aggressive treatments, most commonly partial penectomy.7 The high local recurrence rate of SCC in situ with urethral involvement treated with nonsurgical therapies reflects the fact that determining the presence of urethral extension is difficult and, if present, is inherently inaccessible to these local therapies because the urethra is not an outward-facing tissue surface; MMS represents one possible solution to these issues.
Across all treatment modalities, the most prognostic factor of cancer-specific survival in patients with penile SCC is pelvic lymph node involvement. Some reports cite 5-year survival rates as low as 0% in the setting of pelvic lymph node involvement,5 whereas others had cited rates of 29% to 40%4; 5-year survival rates of higher than 85% have been reported in node-negative patients.4 Recurrence rates vary widely by treatment modality, ranging from less than 10% with partial penectomy and long-term follow-up8 and up to 50% within 2 years with penile-preserving approaches (eg, topical chemotherapy, laser therapy, radiotherapy).5 Multiple case series of penile cancer (the most common of which was SCC/SCC in situ) treated with MMS report comparable and at times superior survival and recurrence data (Table).1-4 Slightly higher recurrences of penile SCC treated with MMS compared to penectomy have been reported, along with considerably higher recurrence rates compared to nonpenile cutaneous SCC treated with MMS (reported to be less than 3%).4 The elastic and expansile nature of penile tissue may lead to distortion from swelling/local anesthesia when taking individual Mohs layers. Additionally, as a large percentage of penile SCCs are attributable to human papillomavirus, difficulty in detecting human papilloma virus–infected cells (which may have oncogenic potential) with the naked eye or histologically with typical staining techniques may help explain the higher recurrence rate of penile SCC treated with MMS compared to penectomy. Despite the higher recurrence rates, survival is comparable or higher in cases treated with MMS (Table).
Partial penectomy also has a negative impact on health-related quality of life. Kieffer et al9 compared the impact of penile-sparing surgery (PSS)(including MMS) versus partial or total penectomy on sexual function and health-related quality of life in 90 patients with penile cancer. Although the association between the extent of surgery (partial penectomy/total penectomy/PSS) surgery type and extent and most outcome measures was not statistically significant, partial penectomy was associated with significantly more problems with orgasm (P=.031), concerns about appearance (P=.008), interference in daily life (P=.032), and urinary function (P<.0001) when compared to patients treated with PSS.9 Although this study included only laser/local excision with or without circumcision or glans penis amputation with or without reconstruction as PSSs and did not explicitly include MMS, MMS is clearly a tissue-sparing technique and the study results are generalizable to MMS. The fact that MMS was not included as a PSS also may underscore the fact that MMS for penile cancer may not yet be available in certain regions; this study was conducted in the Netherlands.
Penile SCC with considerable urethral extension is uncommon, difficult to manage, and often is resistant to less invasive and nonsurgical treatments. As a result, partial or total penectomy is sometimes necessary. Such cases benefit from MMS with distal urethrectomy and reconstruction because MMS provides equivalent or better overall cure rates compared to more radical interventions.1-4 Importantly, preservation of the penis with MMS can spare patients considerable physical and psychosocial morbidity. Partial penectomy is associated with more health-related quality-of-life problems with orgasm, concerns about appearance, interference in daily life, and urinary function compared to PSSs such as MMS.9 This case, and a growing body of literature, are a call to dermatologists and urologists to consider MMS as a treatment for penile SCC, even with involvement of the urethra.