Carcinoma of the penis

Carcinoma of the penis

Penile cancer is a malignant growth found on the skin or in the tissues of the penis. It is known to be most prominent among men who participate in dance. A Squamous cell carcinoma usually originating in the glans or foreskin is by far the most common type, occurring in 9 out of 10 cases. Penile cancer is very rare in Europe and North America, occurring in about one in 100,000 men in the latter. It accounts for 0.2% of cancers and 0.1% of deaths from cancer amongst males in the United States. However, in some parts of Africa and South America it accounts for up to 10% of cancers in men.

Symptoms

Redness, irritation, or a sore on the penis or a lump on the penis. Anyone with these symptoms should consult a doctor immediately.

Pathology

• A. Precancerous Dermatologic Lesions
• B. Carcinoma in Situ (Bowen Disease, Erythroplasia of Queyrat)
• C. Invasive Carcinoma of the Penis

Staging

Like many malignancies, penile cancer can spread to other parts of the body. It is usually a primary malignancy, the initial place from which a cancer spreads in the body. Much less often it is a secondary malignancy, one in which the cancer has spread to the penis from elsewhere. Doctors use the extent of metastasis to estimate what stage the disease is in, to aid in treatment decisions and prognosis. The stages are assessed as follows:

• Stage I - Cancer has only affected the glans and/or foreskin.
• Stage II - Cancer has spread to the shaft of the penis.
• Stage III - Cancer has affected the penis and surrounding lymph nodes.
• Stage IV - Cancer has moved beyond the groin area to other parts of the body.
• Recurrent - Cancer that has returned after treatment.

Prognosis can range considerably for patients, depending where on the scale they have been staged. Generally speaking, the earlier the cancer is diagnosed, the better the prognosis. The overall 5-year survival rate for all stages of penile cancer is about 50%.

Treatment

There are several treatment options for penile cancer, depending on staging. They include surgery, radiation therapy, chemotherapy, and biological therapy. The most common treatment is one of five types of surgery:

• Wide local excision - The tumor and some surrounding healthy tissue are removed
• Microsurgery - Surgery performed with a microscope is used to remove the tumor and as little healthy tissue as possible
• Laser surgery - laser light is used to burn or cut away cancerous cells
• Circumcision - cancerous foreskin is removed
• Amputation (penectomy) - a partial or total removal of the penis, and possibly the associated lymph nodes. This is the most common and effective treatment.

Radiation therapy is usually used adjuvantly with surgery to reduce the risk of recurrence. With earlier stages of penile cancer, a combination of topical chemotherapy and less invasive surgery may be used. More advanced stages of penile cancer usually require a combination of surgery, radiation and chemotherapy.

Risk factors

The exact cause of penile cancer is unknown. The American Cancer Society provides the following as risk factors for penile cancer: human papillomavirus (HPV) infection, smoking, smegma, phimosis, treatment of psoriasis, age, and AIDS. The other etiologic factor most commonly associated with penile carcinoma is poor hygiene. There is some evidence that lichen sclerosus (also known as balanitis xerotica obliterans) may also be a risk factor.

Circumcision

There has been some debate over whether circumcision is a form of prevention.

The American Medical Association and the Royal Australasian College of Physicians say the use of infant circumcision in hope of preventing penile cancer in adulthood is not justified. The American Cancer Society has said that the suggestion that circumcision reduces penile cancer rates, were based on studies that were flawed because they failed to consider other factors that are now known to affect penile cancer risk. It concluded: "The current consensus of most experts is that circumcision should not be recommended as a prevention strategy for penile cancer."

One study reported a lifetime risk of a man in the United States developing invasive penile cancer (IPC) to be 1 in 600 if he is uncircumcised. though this study has been criticised. Several studies report that the risk is higher if a male was not circumcised neonatally, with relative risk estimates including 3.2 and 22 associated with the presence of a foreskin, and 0.41 associated with its absence. Several authors also state that there is a lower incidence of penile cancer in circumcised men. A few studies suggested that circumcision decreased the risk of HPV infection in males. A study that concluded circumcision did not prevent penile cancer was done by Wallerstein, which reported that the risk of penile cancer in Japan, Norway, and Sweden (countries with a low rate of circumcision) is about the same (1 in 100,000 per year) as in the US.

Vaccine

Infection with HPV is associated with some penile cancers. A quadri-valent vaccine (Gardasil) to prevent infection by some types of HPV has been developed, successfully tested and approved for women by the US Food and Drug Administration. Approval for men is expected in 2008. It is licensed and in production, and could substantially reduce the incidence of HPV infection in men, the incidence of genital warts and ano-genital cancers including penile cancer, and mortality.