The Role of 5α-Reductase Inhibitors on Prevention and Hormonal Treatment of Prostate Cancer

Abstract

Aim: Although testosterone generates the main part of serum androgens, the main prostatic androgen is dihydrotestosterone. Dihydroestosterone is produced from testosterone by 5 alpha-reductase. Dihydrotestosterone has some roles on different diseases as benign prostate hyperplasia and prostate cancer in human. We evaluated the role of 5a-reductase inhibitors on the treatment and prevention of prostate cancer.

New Findings: Recently, pure antiandrogens targeting androgen receptors or medical and surgical castration are used in hormonal treatment of prostate cancer. However, these treatments reduced the tumoral mass and the activity of androgen receptors, prostate cancer reactivated in 18-30 months. New drugs that affect the different levels of androgen-androgen receptor pathway are needed to increase the affectivity of treatment. One of these drugs is 5 alpha-reductase inhibitors. There two wide clinical trials on 5 alpha-reductase inhibitors as dutasteride and finasteride. The lower incidences of prostate cancer in patients with 5 alpha-reductase inhibitors were reported in these trials. On the other hand, it is reported that more aggressive tumors were seen with 5 alpha-reductase inhibitors in comparison with placebo.

Conclusion: Clinical trials with finasteride and dutasteride are encouraging. On the other hand, wide clinical trials are needed to show the possible side effects 5 alpha-reductase inhibitors and the role of androgens in both prostate and other systems.