A drug used to treat enlarged prostate or hair loss in men has been shown to have a long-term protective effect against prostate cancer.

The study, led by Fred Hutchinson Cancer Research Center biostatistician Dr. Joe Unger and recently published in Journal of the National Cancer Institute, linked data from a large prostate cancer clinical trial conducted by the clinical trial network SWOG with Medicare claims data to determine that the steroid tablet finasteride could protect men from developing the cancer for up to 16 years.

The original NCI-funded study, known as the Prostate Cancer Prevention Trial, set out to determine if finasteride (also known as Proscar or Propecia) could prevent prostate cancer in men ages 55 and older. That study, which came to an end in 2003, found finasteride use for seven years reduced a man’s risk of developing prostate cancer by 25 percent and that the protective benefit lasted through that seven-year period, which is how long the study followed participants.

Unger and his colleagues went back to the PCPT cohort of nearly 19,000 healthy men (half of whom were given finasteride and half whom received a placebo) to see if finasteride offered a longer-term benefit.

Read the full article about the prostate cancer findings around finasteride by Diane Mapes at Fred Hutch News Service.