Background: In the Prostate Cancer Prevention Trial (PCPT), finasteride significantly reduced the risk of prostate cancer but was associated with an increased risk of high-grade disease. With up to 18 years of follow-up, we analyzed rates of survival among all study participants and among those with prostate cancer.
Methods: We collected data on the incidence of prostate cancer among PCPT participants for an additional year after our first report was published in 2003 and searched the Social Security Death Index to assess survival status through October 31, 2011.
Results: Among 18,880 eligible men who underwent randomization, prostate cancer was diagnosed in 989 of 9423 (10.5%) in the finasteride group and 1412 of 9457 (14.9%) in the placebo group (relative risk in the finasteride group, 0.70; 95% confidence interval [CI], 0.65 to 0.76; P<0.001). Of the men who were evaluated, 333 (3.5%) in the finasteride group and 286 (3.0%) in the placebo group had high-grade cancer (Gleason score, 7 to 10) (relative risk, 1.17; 95% CI, 1.00 to 1.37; P=0.05). Of the men who died, 2538 were in the finasteride group and 2496 were in the placebo group, for 15-year survival rates of 78.0% and 78.2%, respectively. The unadjusted hazard ratio for death in the finasteride group was 1.02 (95% CI, 0.97 to 1.08; P=0.46). Ten-year survival rates were 83.0% in the finasteride group and 80.9% in the placebo group for men with low-grade prostate cancer and 73.0% and 73.6%, respectively, for those with high-grade prostate cancer.
Conclusions: Finasteride reduced the risk of prostate cancer by about one third. High-grade prostate cancer was more common in the finasteride group than in the placebo group, but after 18 years of follow-up, there was no significant between-group difference in the rates of overall survival or survival after the diagnosis of prostate cancer. (Funded by the National Cancer Institute.).