Efficacy and safety of finasteride therapy for benign prostatic hyperplasia

results of a 2-year randomized controlled trial (the PROSPECT Study)

Nickel, J. Curtis MD, FRCSC
Fradet, Yves MD, FRCSC
Boake, Rex C. MD, FRCSC
Pommerville, Peter J. MD, FRCSC
Perreault, Jean-Paul MD, FRCSC
Afridi, Salim K. MD, FRCSC
Elhilali, Mostafa M. MD, FRCSC

Dr. Nickel is professor of urology at Queen's University, Kingston, Ont.; Dr. Fradet is professor in the Research Department, Laval University, Sainte-Foy, Que.; Dr. Boake is a urologist at the University of Alberta Hospitals, Edmonton, Alta.; Dr. Pommerville is a urologist at the Victoria General Hospital, Victoria, BC; Dr. Perreault is professor of urology, Universite de Montreal, Montreal, Que.; Dr. Afridi is chief of urology, St. Paul's Hospital, Saskatoon, Sask.; and Dr. Elhilali is professor of urology at McGill University, Montreal, Que.
(and the PROSPECT Study Group) Members of the PROSPECT Study (PROscar Safety Plus Efficacy Canadian Two-year Study) Group are listed at the end of the article.
Reprint requests to: Dr. J. Curtis Nickel, Department of Urology, Queen's University, Kingston General Hospital, Kingston ON K7L 2V7

CMAJ Canadian Medical Association Journal 155(9):p 1251-1259, November 1, 1996.

Objective

To evaluate the efficacy and safety of 2 years' treatment of moderate benign prostatic hyperplasia (BPH) with finasteride.

Design

Double-blind, parallel-group, placebo-controlled, multicentre, prospective randomized study.

Setting

Outpatient care in 28 centres across Canada.

Participants

Men aged 45 to 80, in good health, with moderate BPH and no evidence of prostate cancer. A total of 613 men were entered into the study; 472 completed the 2 years of treatment.

Intervention

After 1 month of receiving a placebo (run-in period), patients were given either finasteride (5 mg/d) or a placebo for 2 years.

Outcome measures

Efficacy: changes from baseline in BPH symptom scores, maximum urinary flow rates and prostate volume. Safety: onset, course and resolution of all adverse events during the treatment period.

Results

In the efficacy analyses the mean BPH symptom scores decreased 2.1 points (from 15.8 to 13.7) in the finasteride group, as compared with a decrease of 0.7 points (from 16.6 to 15.9) in the placebo group (p less or equal to 0.01). The maximum urinary flow rate increased by a mean of 1.4 mL/s (from 11.1 to 12.5 mL/s) in the finasteride group, as compared with an increase of 0.3 mL/s (from 10.9 to 11.2 mL/s) in the placebo group (p less or equal to 0.01). The mean prostate volume decreased by 21 percent (from a mean volume of 44.1 cm³ at baseline) in the treatment group; it increased by 8.4 percent (from a mean volume of 45.8 cm³ at baseline) in the placebo group (p less or equal to 0.01). In the safety analysis, the proportion of patients who experienced any adverse event was similar in the two groups (81.0 percent in the treatment group and 81.2 percent in the placebo group). However, the incidence of adverse events related to sexual dysfunction were significantly higher in the finasteride group than in the placebo group (ejaculation disorder 7.7 percent v. 1.7 percent and impotence 15.8 percent v. 6.3 percent; p less or equal to 0.01 for both parameters).

Conclusion

Finasteride is a well-tolerated and effective alternative to watchful waiting in the treatment of moderate BPH.