5α-Reductase Inhibitors (5α-ARI)
Landmark COMBAT trial found combination therapy (with alpha blocker) superior to monotherapy. (5)
(5α-ARI) and PCa
Finasteride may reduce the number of overall number of cancers. Some date suggests it may increase the risk of high grade cancers whereas some data does not suggest this.
A retrospective study of 635 men on AS for PCa found that there was no significant difference in grade reclassification of men on (5α-ARI) (1)
Prostate Cancer Prevention Trial- Finasteride reduces number of overall cancers, may increase high grade
Wallerstedt et al - Finasteride reduces overall number of PCa, did not statistically significantly affect long term risk of Gleason 8-10
(5α-ARI) and PCa
Finasteride may reduce the number of overall number of cancers. Some date suggests it may increase the risk of high grade cancers whereas some data does not suggest this.
A retrospective study of 635 men on AS for PCa found that there was no significant difference in grade reclassification of men on (5α-ARI) (1)
Prostate Cancer Prevention Trial- Finasteride reduces number of overall cancers, may increase high grade
- Very large study= more than 4000 patients
- Total prostate cancer in 18% finasteride vs 24% placebo
- High grade cancer (Gleason 7, 8, 9, 10) in 6.4% finasteride vs. 5.1% placebo (2)
Wallerstedt et al - Finasteride reduces overall number of PCa, did not statistically significantly affect long term risk of Gleason 8-10
- Swedish study of 23,000 patients exposed to 5-ARI
- Treatment with 5-ARI decreased the risk for overall PC, and the effect was larger with longer time of exposure (0.1 to 2 years: hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.71 to 0.93; 2 to 4 years: HR = 0.39, 95% CI = 0.32 to 0.47; 4 to 6 years: HR = 0.40, 95% CI = 0.31 to 0.52; and 6 to 8 years: HR = 0.31, 95% CI = 0.16 to 0.60).
- 5-ARI decreased the risk for PC with Gleason Scores 6 and 7
- Did not statistically significantly affect the long-term risk of being diagnosed with a PC with a Gleason Score of 8 to 10 with up to eight years of treatment. (3)
- Dai, Charles, et al. "Impact of 5α-reductase inhibitors on disease reclassification among men on active surveillance for localized prostate cancer with favorable features." The Journal of urology 199.2 (2018): 445-452.
- Thompson, Ian M., et al. "The influence of finasteride on the development of prostate cancer." New England Journal of Medicine 349.3 (2003): 215-224.
- Wallerstedt, Anna, et al. "Risk of Prostate Cancer in Men Treated With 5α-Reductase Inhibitors—A Large Population-Based Prospective Study." JNCI: Journal of the National Cancer Institute (2018).
- l Roehrborn, Claus G., et al. "The effects of combination therapy with dutasteride and tamsulosin on clinical outcomes in men with symptomatic benign prostatic hyperplasia: 4-year results from the CombAT study." European urology 57.1 (2010): 123-131.