Definition of Prostate cancer:

Prostate cancer is cancer that grows in prostate gland. The prostate is a small, walnut-sized structure that makes up part of a man's reproductive system. It wraps around the urethra, the tube that carries urine out of the body.

Causes, incidence, and risk factors:

The cause of prostate cancer is unknown, although some studies have shown a relationship between high dietary fat intake and increased testosterone levels. When testosterone levels are lowered either by surgical removal of the testicles (castration, orchiectomy) or by medication, prostate cancer can slowly get better.

There is no known association with benign prostatic hyperplasia (BPH).

Prostate cancer is the third most common cause of death from cancer in men of all ages and is the most common cause of death from cancer in men over 75 years old. Prostate cancer is rarely found in men younger than 40.

Men at higher risk include African-America men older than 60, farmers, tire plant workers, painters, and men exposed to cadmium. The lowest number of cases occurs in Japanese men and those who do not eat meat (vegetarians).

Prostate cancers are grouped according to how quickly they spread and how different they are from the surrounding prostate tissue. This is called staging. There are several different ways to stage tumors, a common one being the A-B-C-D staging system, also known as the Whitmore-Jewett system:

• Stage A: Tumor is not felt on physical examination, and is usually detected by accident after prostate surgery is done for other reasons.
• Stage B: Tumor is only in the prostate and usually detected during a physical exam or with a blood test (PSA test).
• Stage C: Tumor has spread beyond the prostate but is not in the lymph nodes.
• Stage D: Tumor has spread (metastasized) to lymph nodes or other parts of the body, such as the bone and lungs.

This system also contains several substages.