Penile cancers are rare but have significant morbidity and mortality when detected in late stages. Squamous cell cancers cause over 90% of penile cancers and may be related to HPV infection or to phimosis and/or penile chronic inflammation. Incidence in the US is 0.7 per 100,000 men (106) and 0.8 per 100,000 men in Australia (107). In the developing world, incidence is higher at 4.4 per 100,000 men (108, 109). The peak incidence is during the seventh decade of life (110).
Risk factors for penile SCC include HPV infection, increasing age, smoking tobacco, immunodeficiency, phimosis and men who are uncircumcised (110, 111). Approximately half (48%) of penile cancers are associated with HPV, especially types 16 and 18 (112).
High risk HPV types can cause a precursor lesion, penile intraepithelial neoplasia (PeIN). Undifferentiated PeIN is commonly associated with HPV infection whereas differentiated PeIN is associated with non-viral factors such as chronic inflammation, lichen sclerosis or phimosis (113, 114). The mechanisms whereby PeIN progresses to invasive penile carcinoma are yet to be elucidated.
To date, there remains no consensus on how to screen for penile cancer. Consider specialist referral for any persistent penile lesion after treatment for STIs is completed.
Clinically, PeIN may be subdivided as erythroplasia of Queyrat, Bowen disease, and bowenoid papulosis. Erythroplasia of Queyrat lesions have the highest likelihood of progressing to carcinoma. Penile squamous cell cancers can present in a variety of ways, including a non-healing ulcer or mass, discharge, bleeding, phimosis, change in colour or rash of penile skin.
Biopsy of any suspicious lesion is recommended.
Management depends on the stage of the cancer at diagnosis. If diagnosed early, especially for carcinoma-in-situ lesions, laser surgery, cryotherapy or fluorouracil cream may be considered. Otherwise, the patient will require surgery, radiotherapy and chemotherapy (115). In certain circumstances, penile-preserving surgery may be possible (116).