Endocrine therapies for symptomatic benign prostatic hyperplasia.

OBJECTIVE: To provide a comprehensive overview of the various endocrine therapies being developed and investigated for the treatment of symptomatic benign prostatic hyperplasia (BPH).
METHODS: Peer-reviewed reports in the medical and urologic literature were examined for pertinent information relating to the role of luteinizing hormone-releasing hormone (LHRH) agonists, antiandrogens, 5 alpha-reductase inhibitors, and aromatase inhibitors in the management of BPH. Special attention was given to the scientific rationale and clinical results for each therapy.
RESULTS: LHRH agonists, antiandrogens, and 5 alpha-reductase inhibitors all reduce the androgenic stimulation to the prostate gland. In doing so, they decrease prostate size by 25 percent, but cause a modest improvement in symptom score (3-4 points) and peak urinary flow rate (approximately 2.5 mL/sec). All of these therapies cause a significant decrease in the serum prostate-specific antigen (PSA) concentration, and an effect is maintained as long as the treatment is continued. Side effects are most pronounced for the LHRH agonists, in which impotency and decreased libido are universal phenomena, and least significant for the 5 alpha-reductase inhibitors. Aromatase inhibitors eliminate the estrogenic stimulation to the prostate gland. Although substantial evidence exists to support the role of estrogens in the development and maintenance of BPH, no data from large-scale randomized clinical trials are available to document the clinical usefulness of aromatase inhibitors in the treatment of symptomatic BPH.
CONCLUSIONS: Medications that produce a state of androgen deprivation can reduce the static component of BPH. Of these agents, the 5 alpha-reductase inhibitors have the greatest promise because of their low toxicity profile. The role of the aromatase inhibitors in the treatment of BPH remains to be determined.