Treating Prostate Cancer with Hormonal Therapy
Hormonal Therapy Overview
Hormonal therapy combats 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.
Hormonal therapy targets cancer that has spread beyond the prostate gland and is thus beyond the reach of local treatments such as surgery or radiation therapy. Hormonal therapy is also helpful in alleviating the painful and distressing symptoms of advanced disease. Further, it is being investigated as a way to arrest cancer before it has a chance to metastasize. Although hormonal therapy cannot cure, it will usually shrink or halt the advance of disease, often for years.1
Specific Hormonal Therapies
Hormone therapy used in the treatment of prostate cancer may include the following:
- Luteinizing hormone-releasing hormone (LHRH) agonists act to prevent the testicles from producing testosterone. Examples of these are leuprolide, goserelin, abarelix and buserelin.
- Antiandrogens are employed to block the action of androgens (hormones that promote male sex characteristics). Two examples are flutamide and nilutamide. Drugs of this type are taken daily as pills.
- Drugs that can prevent the adrenal glands from making androgens; two of these are ketoconazole and aminoglutethimide.
- Orchiectomy is a surgical procedure to remove one or both testicles, the main source of male hormones, to decrease hormone production.
- Estrogens (hormones that promote female sex characteristics) can prevent the testicles from producing testosterone. However, estrogens are seldom used today in the treatment of prostate cancer because of the risk of serious side effects.2
Orchiectomy
Surgery to remove the testicles (orchiectomy or surgical castration) is usually an outpatient procedure. The testicles are removed through a small incision in the scrotum; the scrotum itself is left intact. To help offset the operation's psychological toll, some men opt for reconstructive surgery in which the surgeon replaces the testicles with prostheses shaped like testicles.3
Combination Treatments
Anti-androgen treatment is often combined with orchiectomy or LHRH analogs. This combination is called combined androgen blockade (CAB). There is still some debate as to whether CAB is more effective than using orchiectomy or an LHRH analog alone. According to the American Cancer Society, there is a benefit, it appears to be small.4
Use of Estrogens
Estrogens were once the main alternative to orchiectomy for men with advanced prostate cancer. Because of their possible side effects (including blood clots and breast enlargement), estrogens have been largely replaced by LHRH analogs and anti-androgens. Still, estrogens may be tried if androgen deprivation is no longer working.5