Cancer of the penis can occur anywhere along the penile shaft, but most are on the foreskin or head (glans).
It is usually a slow-growing cancer and is curable if discovered early.
Cancer of the penis is rare in the U.S., affecting only one or two men in 100,000. It is almost never seen in those who have been circumcised as babies, which is a major argument in favor of newborn circumcision. Unfortunately, some men do not seek medical attention until after it has spread.
Nearly all penile malignancies are cancers of the skin, the most common being squamous cell carcinoma, similar to squamous cell carcinomas on other parts of the skin such as the face or hands.
Some penile cancers are melanomas, which appear as blue-brown flat growths and tend to spread more rapidly and more widely. Occasionally, the deep tissues of the penis develop cancer, typically sarcomas.
The tumor spreads gradually becoming larger in the area of the skin where it first develops. Ultimately, it spreads to deep tissues inside the body of the penis and to lymph nodes in the groin (inguinal area) or pelvis.
When the cancer is in the penis itself (local) and involves no more than a few nearby inguinal lymph nodes, it can be cured, but cure rates fall rapidly once it spreads to the pelvic lymph nodes.
Once cancer of the penis is found, more tests will be done to determine whether the cancer has spread from the penis to other parts of the body (staging). There are a number of stages:
- Stage 1: cancer cells are found only on the surface of the glans and on the foreskin
- Stage 2: cancer cells are found in the deeper tissues of the glans and have spread to the shaft of the penis
- Stage 3: cancer cells are found in the penis and have spread to the nearby lymph nodes in the groin
- Stage 4: cancer cells are found throughout the penis and the lymph nodes in the groin and/or have spread to other parts of the body
Men who are circumcised at birth, a common practice in the U.S., almost never get penile cancer. If circumcision is performed at puberty, the incidence of cancer is slightly higher, and men who are circumcised as adults experience the same incidence of penile cancer as men who are never circumcised at all.
Cancer of the penis is, in a sense, a disease of poor hygiene. It is believed that the decaying cells of the undersurface of the foreskin (smegma) produce irritation leading to cancer.
In addition, there may be a relationship between venereal warts (condyloma acuminata) and penile cancer.
Recent studies have shown an association between certain types of the virus that causes condylomata (human papilloma virus types 16 and 18) and penile cancer in about one man in three who have penile cancer. These human papilloma virus (HPV) types are also found in women who have cancer in the uterine cervix.
It also has been shown that cancer of the uterine cervix may be higher in the sexual partners of men who are not circumcised.
Penile cancer typically begins as a raised lump or lesion on the penis. It can begin more as an area of unexplained change in the color of the skin.
Like most cancers, this is diagnosed by means of a biopsy.
Treatment is determined by the tumor size and staging. If the tumor is small and local, it can be treated surgically, chemically, or with radiation or laser without major damage to the appearance or function of the penis.
If it has penetrated the deeper penile tissues or is large, surgery is the preferred treatment for most men. Radiation is an option but results are less certain.
If the tumor has spread to lymph nodes, surgery or radiation is used. Chemotherapy is of little value in extensive carcinoma of the penis.