Prostate cancer is a major health problem for the aging male population. Despite hormonal dependence, the inevitable emergence of
androgen insensitive
tumors, which have a dismal prognosis, highlights the need to develop prevention strategies such as
chemoprevention. An acceptable agent must interfere with either the process of
carcinogenesis or
tumor growth, and have minimal toxicity. In clinical studies,
5 alpha-reductase inhibitors have been shown to suppress serum and intraprostatic levels of
dihydrotestosterone, an important promoter of
prostate cancer, leading to reduction in prostate size and suppression of glandular cell activity as measured by
prostate specific antigen secretion. In addition,
5 alpha-reductase inhibitors have demonstrated an excellent safety profile and tolerability in 12 month controlled clinical trials. No significant metabolic effects have been observed in
gonadotropin secretion, spermatogenesis, serum
lipids or
glucose tolerance. The efficacy and safety of
5 alpha-reductase inhibitors in studies to date, combined with the
androgen dependence of
tumor production, strongly supports investigating their use for
chemoprevention of
prostate cancer.