Penile cancer
Penile cancer is a rare malignancy that occurs on the skin and deeper tissues of the penis, often presenting as small lesions or sores. It primarily affects men over the age of 55, with risk factors including exposure to human papillomavirus (HPV), phimosis, and smoking. The disease is more prevalent in certain regions, accounting for about 1% of cancers in developed countries, but rising to 10% in parts of Asia, Africa, and South America. Symptoms may include sores, rashes, or foul-smelling material under the foreskin, particularly in uncircumcised men. Diagnosis is typically made through biopsy, and staging helps determine the extent of the disease.
Treatment options usually involve surgical removal of the cancerous tissue, with more radical procedures, such as penectomy, considered for advanced cases. The prognosis varies significantly, influenced by the stage of cancer at diagnosis and lymph node involvement. The HPV vaccine can help lower the risk, and while circumcision in infancy is associated with lower rates of the disease, its preventive effect is not fully supported by medical consensus. Early detection and treatment are crucial for improving outcomes, highlighting the importance of awareness and routine health examinations for men's health.
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Subject Terms
Penile cancer
ALSO KNOWN AS: Cancer of the penis, penile carcinoma, penile malignancies, penile carcinoma in situ (CIS), erythroplasia of Queyrat, genital Bowen disease
RELATED CONDITIONS: Male reproductive cancers, urethral cancer, dermatologic malignancies, squamous cell carcinomas, human papillomavirus infections, testicular cancer, prostate cancer, recurrent balanitis, phimosis
DEFINITION: Penile cancer is cancer on the skin and deeper tissues of the penis.
Risk factors: Exposure to human papillomavirus (especially subtypes 8, 16, 39, and 51) and lack of circumcision are major risk factors for the development of penile cancer. Age is also a risk, as most cases occur in men over fifty-five, with an average age at diagnoses being sixty. Smoking is an additional risk factor. The most important risk is phimosis, a narrowing of the opening of the prepuce that results in a foreskin that cannot be retracted. This is a painful condition in which the foreskin of uncircumcised men becomes inflamed with a chronic buildup of smegma under the foreskin, often due to a lack of hygiene. Circumcision is an operation, usually done on newborns, that removes the foreskin from the penis. Approximately 80 percent of American men are circumcised, but rates vary, and circumcision is rare in many parts of the world.
Etiology and the disease process: Penile cancer most commonly begins as small lesions (sores) on the skin of the glans of the penis or prepuce, the opening of the foreskin. Lesions are usually squamous cell carcinomas, which may remain on the skin, invade deeper into the tissues, and spread (metastasize) into the bloodstream and lymph nodes. Delays in seeking treatment due to misinformation, embarrassment, and fear result in many cases being diagnosed at an advanced stage. Penile cancer that has metastasized into the adjacent lymph nodes can cause death from sepsis or hemorrhage. Metastasis into the blood, liver, bone, and brain is rare unless the cancer has been untreated and has reached a very advanced stage. If left untreated until later stages, the treatment for penile cancer may require removal of part or all of the penis and can be fatal.
Incidence: Penile cancer is rare in developed nations, accounting for about 1 percent of cancers among men. In the United States, around 1,300 cases are diagnosed each year. However, in Asia, Africa, and South America, it accounts for around 10 percent of cancers in men.
Symptoms: Symptoms include sores, rashes, or skin growths on the penis and foul-smelling material under the foreskin of uncircumcised men. The foreskin can obscure a lesion that is not healing and may not be detected until tissue death (necrosis) produces material under the foreskin that has a foul odor.
Screening and diagnosis: Screening for penile cancer is not customary, but men should have a genital examination as part of their routine physicals. Diagnosis is made from biopsy and is more likely to be performed early on a suspected lesion if patients seek care from a urologist. Staging the cancer determines how much it has spread (invasiveness) and if lymph nodes are affected. Biopsy of sentinel lymph nodes also helps determine the degree of spread to the lymphatics. Staging generally uses the TNM (tumor/lymph node/metastasis) system, which classifies the tumor based on the presence or absence of spread, lymph node involvement, and more distant metastases.
Treatment and therapy: Treatment for penile cancer is usually surgery to remove the cancerous area. Chemotherapy may also be used to kill cancer cells. Although laser therapy can sometimes be used, most often, more radical forms of surgery are necessary. However, penile cancer can usually be removed with little to no damage to the penis if detected early. Penectomy is surgery that removes all or part of the penis. A partial penectomy may preserve sexual function and the ability to urinate from the penis. A total penectomy completely removes the penis and creates a new outlet for urination, usually located behind the testicles. Plastic surgery to create a new penis is possible, but function may be limited. Mohs micrographic surgery is an advanced technique that uses microscopy to remove cancerous tissue and allows for maximal sparing of penile tissue. Chemotherapy may be applied topically or, in cases of metastatic cancer, given systemically.
Prognosis, prevention, and outcomes: Prognosis depends on the time between the first appearance of penile cancer and initiation of treatment, and the status of lymph nodes is the most important clinical indicator of prognosis. The occurrence of penile cancer is rare in men circumcised as newborns. However, circumcision itself carries risks, and medical authorities have not agreed that there is enough evidence to support recommendations for routine neonatal circumcision. Adult circumcision does not prevent the development of the disease. The human papillomavirus vaccine can reduce the incidence of penile cancer. However, HPV infection is responsible for about 60 percent of cases of penile cancer.
Outcomes depend on the state of progression (especially lymph node involvement) when the cancer is detected, treatments used, and response to treatment. Five-year survival rates in men without lymph node involvement who have had surgical treatment average 79 percent, whereas five-year survival rates are approximately 51 percent in men with lymph node involvement and 9 percent in cases with distant metastasis. In cases where penis-sparing therapies have been used, surveillance for recurrence is essential. Any consideration of outcomes should address the emotional toll of the disease and necessary treatments.
Bibliography
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