Metastatic Prostate Cancer Treatment
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 used for metastatic prostate cancer treatment, taken as periodic injections, prevents the brain from signaling the testicles to produce androgens.
Either surgical castration (orchiectomy) or medical castration (hormonal drug therapy) can produce a striking response. Both treatments cause tumors and lymph nodes to shrink and PSA (prostate-specific antigen) levels to fall. However, both castration methods can cause:
Medical castration by treatment with hormonal drug therapy can cause breast enlargement and can increase a man's risk of cardiovascular problems, including heart attacks and strokes.
Hormonal therapy has been tried in many combinations. One approach, known as maximum androgen blockade or complete hormonal therapy, combines castration (either surgical or medical) with an antiandrogen pill, taken daily for months or years. However, studies show that single hormone treatments have similar effectiveness compared to maximum androgen blockade. In addition, combining surgery with hormonal therapy appears to relieve symptoms.
Medical castration by hormonal therapy can be costly, but, unlike surgical castration, its effects can be reversed by stopping the drug. Moreover, halting hormone treatments will sometimes, paradoxically, temporarily interrupt the progress of an advanced and advancing cancer.
Unfortunately, hormonal therapy for treating metastatic prostate cancer works only for a limited time. Remissions typically last two to three years. Eventually, cancer cells that don't need testosterone begin to flourish, and cancer growth resumes. When that happens, a variety of other, second-line hormonal-type drugs (for example, hydrocortisone or progesterone) may be tried.