Propecia (Finasteride 1 mg), is used for the treatment of male pattern baldness. Researchers have found that use of this drug lowers the reading on a PSA screening test.

This means that men taking Propecia may have prostate cancer even if their PSA readings are in a range considered normal for their age.

Propecia's higher strength cousin, Proscar (finasteride 5 mg) had already been shown to reduce PSA levels warranting the recommendation to cut the PSA concern level in half.

This research shows that Propecia lowers the PSA the same as Proscar, and in younger males, this could mask the fact that they have prostate cancer.

The study, published by Anthony V. D'Amico, MD, PhD, of Brigham and Women's Hospital, and Claus G. Roehrborn, MD, of the University of Texas Southwestern Medical Center is available at the online edition of The Lancet.