Antiandrogenic drugs.

BACKGROUND: Prostate cancer is the most frequent cancer diagnosed in American men today. Currently, about half of all patients with newly diagnosed prostate cancer present with metastatic diseases.
METHODS: Antiandrogenic drugs, or more appropriately androgen-receptor antagonists, represent a group of compounds that currently have played a limited role in the treatment of metastatic prostate cancer. Their method of action is primarily one of blocking androgens at their receptor sites in target tissues. They generally are classified as steroidal or nonsteroidal compounds. Cyproterone acetate and megestrol acetate are synthetic steroidal antiandrogenic drugs that, not only compete with testosterone and dihydrotestosterone for androgen receptors, but also have progestational activity and reduce pituitary luteinizing hormone and subsequently plasma testosterone. Nonsteroidal antiandrogenic agents (flutamide, Casodex [ICI Pharmaceuticals, England], and nilutamide) block cellular binding of androgens only, and there is no reduction of testosterone levels.
RESULTS: Antiandrogenics have been used in numerous trials both in Europe and the United States. This group of compounds have been used as monotherapy and in combination therapy, ie, with orchiectomy or with LHRH agonists.
CONCLUSIONS: Currently, antiandrogens are used primarily in conjunction with conventional medical or surgical castration to achieve maximal androgen deprivation; however, ongoing clinical studies are comparing these compounds alone against standard hormonal therapy. It seems probable that antiandrogens will play an expanding role in the treatment of metastatic prostate cancer as well as having a role in the treatment of prostate cancer.