Prostate cancer is an abnormal, uncontrolled growth of cells that results in the formation of a tumor in the prostate gland. Prostate, the walnut sized gland, is a part of the reproductive system which lies deep in the pelvis. It is located in front of the rectum and underneath the urinary bladder and surrounds the urethra, (the urine tube running from the bladder, through the prostate and the penis). It contains gland cells that produce some of the seminal fluid, which protects and nourishes sperm cells in semen and supports the ejaculatory ducts, or sperm tubes. The prostate continues to grow till a man reaches adulthood and is maintained after it reaches normal size as long as male hormones are produced.

Prostate cancer begins most often in the outer part of the prostate. It is the most common cancer in men older than age 50. In most men, the cancer grows very slowly. In fact, many men with the disease will never know they have the condition. Early prostate cancer is confined to the prostate gland itself, and the majority of patients with this type of cancer can live for years with no problems. In some cases, it may spread from the prostate to nearby lymph nodes, bones or other organs. This spread is called metastasis. Most Prostate cancers originate in the posterior prostate gland, the rest originate near the urethra.