What is penile cancer?

Penile cancer is a rare disease in which malignant cells develop in the skin and/or soft tissues of the penis.

Who gets penile cancer?

The disease generally affects older men and is rare in Western countries, involving approximately 1 out of every 100,000 men. It is more common in places such as Africa and Asia. Circumcision just after birth, a procedure in which the covering of the tip of the penis is removed, appears to protect men from getting the disease. The risk of penile cancer is about 3 times higher for men who are uncircumcised, or are circumcised later in life. Poor hygiene and having a sexually transmitted disease (such as HPV, or human papilloma virus) may also increase a man's risk of developing cancer of the penis.

So what are the symptoms?

Penile cancer may appear as a red or hardened area on the skin of the penis. The cancer can also cause the glands or lymph nodes in the groin to enlarge. As the disease progresses, the cancer cells may form a raised lesion that can sometimes cause parts of the tissue of the penis to die and erode away.

How is it diagnosed?

After performing a physical examination, it is usually necessary to obtain a tissue sample, or biopsy, of the cancerous cells for examination under the microscope. Tissue is obtained by inserting a needle into the area of abnormal skin or tissue or by removing the entire tumor in a surgical procedure called a wide local excision. Cancers are described by the type of cells from which they arise. More than 95% of penile cancers are squamous cell carcinomas, a type of cell that is flat and thin and makes up the outer layer of the skin. Once the cancer is diagnosed, a procedure called a cystoscopy may be performed, in which a tiny camera (scope) is inserted through the opening of the penis and advanced all the way to the bladder to look for spread of cancer to the urethra (tube connecting the bladder to the penis) and/or bladder.

How is it staged?

Once a penile cancer is found, it is necessary to perform more tests to see if the tumor has spread so that appropriate treatment can be recommended. These may involve imaging studies such as CT scans or MRI scans, or procedures such as a cystoscopy (see above).

The extent of the tumor spread is also referred to as the "stage". The staging system for penile cancer is the "TNM" system described by the American Joint Committee on Cancer. The "T" describes the size or invasiveness of the tumor; the "N" describes the spread of the tumor to any glands, or lymph nodes, near the tumor; and the "M" describes any distant spread, or metastasis, to other organs or sites of the body. Grade, or how well the tumor cells are organized, is also used in making treatment decisions, but is not included in the official "TNM" staging system. The different stages of penile cancer are as follows:

* Tis: carcinoma in situ, or a tumor that involves only the cells in which it began and has not spread to other tissues
* Ta: a tumor that has not invaded through the outmost layer of cells, or epithelium, that makes up the skin
* T1: a tumor that has invaded through the epithelium to involve the connective tissue below the skin
* T2: a tumor that has invaded through the connective tissues to involve the corpus spongiosum or corpus cavernosum, the deep spongy tissues of the penis
* T3: a tumor that has invaded the urethra (the tube that connects the bladder and penis) or prostate gland
* T4: a tumor that has invaded other structures such as the bones of the pelvis
* N0: the cancer has not spread to glands or lymph nodes in the groin or pelvis
* N1: the cancer has spread to a single shallow gland or lymph node in the groin, called a superficial inguinal lymph node
* N2: the cancer has spread to more than one shallow gland or lymph node in the groin, either or one side or both sides of the groin
* N3: the cancer has spread to one or more deep glands or lymph nodes in the groin, called deep inguinal lymph nodes, or has spread to lymph nodes in the pelvis (such as internal iliac or hypogastric lymph nodes, external iliac lymph nodes, or obturator lymph nodes)
* M0: the cancer has not spread to distant organs or sites of the body
* M1: the cancer has spread to distant organs or sites of the body
* The different grades of penile cancer are as follows:
o G1: well-organized tumor cells; considered low grade
o G2-3: moderately-organized tumor cells; considered intermediate grade
o G4: poorly-organized tumor cells; considered high grade

The overall stage of the tumor (Stage I, II, III, or IV) is then based on a combination of the T, N, and M categories. A tumor may also be described as relapsing. This means that the tumor has come back after it was originally treated. It may return to the site where it first started or to other areas of the body.

What is the prognosis of penile cancer?

The prognosis is based largely on the stage of the tumor, as well as the grade. Patients with low grade and low stage tumors have an excellent prognosis and long-term survival. Patients with tumors that have not spread to the glands or lymph nodes likewise have an excellent prognosis, with 95% survival at 5 years from diagnosis. The survival rate decreases when the disease spreads to the lymph nodes in the groin, and very few patients are alive at 5 years if the tumor has spread to lymph nodes in the pelvis.

What are the recommended treatment options?

Surgery

Surgery forms the foundation of treatment and can involve excision of the primary tumor and foreskin only, the entire penis, and/or the lymph nodes in the groin and pelvis. Patients with small Tis, Ta, or T1 tumors generally have only the foreskin and primary tumor (tumor involving the penis itself) resected. This is called a wide local excision. Larger tumors generally require removal of the entire penis. For patients with T2 and higher tumors without lymph nodes that can be felt on exam or seen on imaging studies, surgical removal of the shallow nodes on both sides of the groin is done in addition to resection of the primary tumor. If multiple groin lymph nodes are found to be involved with cancer, or if a patient presents with groin nodes that can be felt on exam or seen on imaging studies, the surgeon may also remove nodes from both the deep groin and pelvis to assess for further spread of disease.

Radiation Therapy

Radiation involves the use of high energy x-rays aimed at the tumor or the area from where the tumor was removed. Both external radiation (radiation that comes from a machine rotating around the patient) and brachytherapy (a procedure in which radioactive seeds are inserted directly into the tumor) can be used. Radiation therapy can be used alone for some T1 lesions and T2 lesions that are low grade, or it can be used with or without chemotherapy following surgery in patients who have advanced disease. The role of the radiation here is to decrease the risk of cancer coming back in the pelvis, groin, or penis.

Chemotherapy

Chemotherapy is most commonly used in patients whose cancer has spread throughout the body to distant sites, and who need systemic therapy (therapy that reaches all parts of the body). Chemotherapy is used less often in the treatment of localized penile cancer, which is cancer that has not spread to distant sites. It can be used before surgery when patients present with more advanced disease, such as spread to the lymph nodes in the groin or pelvis. Drugs such as bleomycin, cisplatin, and methotrexate have been reported as achieving modest tumor responses in selected patients. Chemotherapy is also occasionally used in combination with radiation after surgery for patients who have advanced disease.

Other Options

Laser surgery and Mohs' microsurgery are occasionally used for very early tumors that have not invaded into the deeper tissues of the penis. Very superficial or shallow tumors may also be treated with fluorouracil cream, a kind of topical chemotherapy, to kill the tumor cells.

How will I be followed after my treatment?

Patients who have undergone treatment for penile cancer should be seen and carefully examined by a physician every 2 to 4 months for the first year. This is especially important for those patients who have not undergone removal of lymph nodes. The risk of developing spread to lymph nodes in the groin is greatest in the first 6 months after treatment. The cornerstone of follow-up care is physical examination, although sometimes imaging studies such as ultrasound of the groin may detect spread of cancer to lymph nodes even before those nodes can be felt on examination. CT scanning of the pelvis is also helpful in detecting abnormal nodes which cannot be detected on physical examination. If a patient has undergone removal of the penis, reconstruction of the penis by plastic surgery may be considered once a patient has been in remission for 2 years or more.