A very large study called the Prostate Cancer Prevention Trial randomized more than 18,000 men to take finasteride or placebo for seven years. Finasteride, also known as Proscar, reduces the conversion of testosterone to dihydrotestosterone, thereby reducing the size of the prostate and controlling male pattern baldness.
The new research tracked the men for up to 18 years and found a reduced incidence of prostate cancer among men taking finasteride. Just 10.5% of those on finasteride were diagnosed with prostate cancer, compared with 14.9% of those on placebo. Unfortunately, though, those taking the drug who did develop prostate cancer were more likely to have an aggressive form of the disease.
The most important outcome of the entire study, long-term survival, did not differ between the two groups, suggesting that finasteride did not affect mortality. It is not without side effects, however, so men should be well-informed before planning to take this drug for an extended period of time.
There is more information on prostate enlargement and prostate cancer screening in our book, Top Screwups Doctors Make and How to Avoid Them.
