For newly diagnosed prostate cancer that has spread beyond the prostate gland, or for cancer that has recurred, hormonal therapy may relieve symptoms and slow the progress of the disease.

Hormonal therapy fights prostate cancer by cutting off the supply of male hormones (androgens) such as testosterone that encourage prostate cancer growth.

Hormonal control can be achieved by surgery to remove the testicles (the main source of testosterone) or by drugs.

Surgery to remove the testicles (orchiectomy or surgical castration) is generally performed as an outpatient procedure in which the testicles are removed through a small incision in the scrotum. The scrotum itself is left intact.

A variety of hormonal drugs can produce a medical castration by cutting off supplies of male hormones. Female hormones (estrogens) block the release and activity of testosterone. Antiandrogens block the activity of any androgens circulating in the blood. Still another type of hormone, taken as periodic injections, prevents the brain from signaling the testicles to produce androgens.

Either surgical castration or hormonal drug therapy can cause tumors and lymph nodes to shrink and PSA levels to fall -- but both castration methods can cause hot flashes, impotence, and a loss of interest in sex. Hormonal drug therapy also can cause breast enlargement and can increase a man's risk of heart attacks and strokes.

Unlike surgical castration, the effects of hormonal therapy can be reversed by stopping the drug.

Unfortunately, hormonal therapy for metastatic disease works only for a limited time. Remissions typically last 2 to 3 years. Eventually, cancer cells that don't need testosterone begin to flourish, and cancer growth resumes.