Penis cancer is uncommon, representing 0.5% of all cancers in men in the United States and Europe. However, penile cancer accounts for up to 10% of cancers in men on the continents of Asia, Africa, and South America. It primarily affects men between the ages of 50 and 80, although 25% of cases involve men under the age of 50.
Risk factors predisposing men to penile cancer include cigarette smoking, poor penile hygiene and inflammation, lack of circumcision, and human papilloma virus (HPV) infection. Genital warts are a result of HPV infection, and are more common in men with early age at onset of sex, and multiple sexual partners. Penile cancer is rare in men who were circumcised as infants.
Penile cancer can occur anywhere on the penis. It is responsive to treatment, particularly in early stages.
Penis cancer usually begins as a small lump, ulcer, or discoloration on the glans (head) or foreskin of the penis, and gradually spreads to involve the remainder of the penis. Pain is not common. In advanced stages, it may develop into an erosive mass with an odorous discharge and bleeding, and can make urination difficult. Penis cancer spreads to the lymph nodes in the groin, leading to swelling and/or pain.
A lesion suspicious for penile cancer requires a biopsy. This is a procedure where either a portion or entire lesion is removed for pathologic analysis. This is typically done under local anesthesia, but larger lesions may require a general anesthetic. The majority of penile cancer is squamous cell carcinoma. Factors affecting treatment include the depth of cancer invasion and tumor aggressiveness (grade).
Once squamous cell cancer of the penis is diagnosed, the physician needs to determine if it has spread. This is done initially by physical examination of the inguinal (groin) lymph nodes. These lymph nodes can also be assessed using imaging such as CT scans or MRI. In addition to the groin lymph nodes, imaging allows evaluation of distant spread to the pelvic lymph nodes, lungs, and other organs of the body. Once the diagnosis, grade, and studies detailed above have been completed, a stage can be assigned to the cancer. Treatment recommendations are based on stage and grade.
Treatment of penis cancer is based on the grade and stage of the cancer and involves addressing the penile lesion, the groin lymph nodes, and metastases. Treatment of the penis involves excising the cancer in its entirety. If the penile lesion is small and flat, it may be amenable to treatment with topical chemotherapy ointments, laser therapy, or microsurgery. Other lesions require surgical excision. Small cancers of the foreskin often are treated with circumcision alone. Advanced cancers require removal of part or all of the penis. Penectomy is performed to preserve as much penile length as possible, maximizing urinary and sexual function without compromising cancer control. Radiation therapy is an option for some men with locally advanced penile cancer.
Once the cancer of the penis is removed, the urologist must then determine if additional treatment is necessary. The first consideration is whether or not the groin lymph nodes require removal (lymphadenectomy). Need for inguinal lymphadenectomy rests on the grade and stage of the tumor. In general, if the lesion is minimally invasive and the grade of the tumor is low, an inguinal lymphadenectomy may not be needed. However, if the grade of the tumor is high and/or the lesion has invaded the deeper tissues of the penis, a lymphadenectomy will likely be recommended. Groin lymph nodes positive for cancer will require resection of the pelvic lymph nodes.
A high tumor burden in the lymph nodes, and/or spread to other organs, may require chemotherapy and/or radiation therapy.
It is important that all men periodically examine their penis for lesions. In patients who are not circumcised, it is imperative that they retract and clean their foreskin daily. Suspicious lesions should be immediately reported to their primary care physician, with referral to a urologist if necessary. Treatment for penile cancer should be administered by physicians at institutions familiar with the management of this rare cancer.
Pow-Sang, MR, et.al. Epidemiology and Natural History of Penile Cancer. Urology 76 (Suppl 2A): S2-S6, 2010.
Solsona, E, et.al. New Developments in the Treatment of Localized Penile Cancer. Urology 76 (Suppl 2A): S36-S42, 2010.
Heyns, CF, et.al. Management of the Lymph Nodes in Penile Cancer. Urology 76 (Suppl 2A): S43-S57, 2010.