5-alpha-Reductase Inhibitors Prevent the Progression of Benign Prostatic Hyperplasia

Abstract

Lower urinary tract symptoms (LUTS) associated with clinical benign prostatic hyperplasia (BPH) are a common occurrence in aging men, causing bother and interference with daily activities and affecting disease-specific quality of life. There is increasing evidence to suggest that, in many patients, the signs and symptoms of BPH are progressive. Progression can be measured as continued growth of the prostate gland; worsening of symptoms, bother, or quality of life; deterioration of urinary flow rate; episodes of acute urinary retention (AUR); and need for prostate-related surgery. Furthermore, it has become clear that the risk of disease progression increases with age as well as with increasing prostate volume and serum prostate-specific antigen (PSA) level. The 5-alpha-reductase inhibitor finasteride has been shown not only to improve symptoms, bother, and quality of life but also to prevent progression to AUR and surgery, with a relative risk reduction of over 50%. As the risk for such progression is higher in patients with larger glands or higher serum PSA values at baseline, it is in those patients that finasteride induces an even greater risk reduction, making it a cost-effective treatment choice for patients with LUTS associated with prostatic enlargement.

Figure 1

Prediction of prostate volume by serum prostate-specific antigen (PSA) level in men stratified by age categories. Adapted from Roehrborn CG et al. Urology. 1999; 53:581–589.

Figure 2

Pooled analysis of 1-year studies of finasteride versus placebo demonstrates an increase in the drug-attributable effect on symptoms and a decrease in the placebo response with (A) increasing prostate size and (B) increasing serum prostate-specific antigen (PSA) level. IPSS, International Prostate Symptom Score. Data from Boyle P et al. Urology. 1996;48:398–405; Boyle P et al. J Urol. 1997;157:134A.

Figure 3

Cumulative incidence of acute urinary retention (AUR) and surgery in the placebo-treated patients in the Proscar Long Term Efficacy and Safety Study stratified by serum prostatespecific antigen (PSA) level at baseline. A linear increase in risk is noted with increasing serum PSA value at baseline for both outcomes.

Figure 4

Incidence rates of (A) spontaneous or precipitated AUR and (B) surgery in placebo- and finasteride-treated patients in the Proscar Long Term Efficacy and Safety Study stratified by prostate-specific antigen (PSA) tertiles. As the risks of AUR and surgery increase with increasing serum PSA level, the relative risk reduction with finasteride becomes greater. Data from Roehrborn CG et al. Urology. 1999;53:473–480.

Figure 5

Cumulative incidence of spontaneous or precipitated acute urinary retention (AUR), surgery, or either event for the (A) placebo-treated patients and (B) finasteride-treated patients in the Proscar Long Term Efficacy and Safety Study. For those who received placebo, these risks increased with increasing serum PSA level, whereas they remained relatively flat for the finasteride-treated patients.

Figure 6

Cumulative probability for acute urinary retention (AUR) or surgery related to benign prostatic hyperplasia (BPH) in the Proscar Long Term Efficacy and Safety Study and during 2 years of open-label extension, during which all patients received finasteride (Fin). The risk for the subjects who had previously received placebo flattened and was similar to that of the finasteride-treated patients during years 5 and 6.

Figure 7

(A) Progression of benign prostatic hyperplasia (BPH). (B) Prevention/reversal of progression of BPH with finasteride. PSA, prostate-specific antigen.