Proscar lowers prostate cancer risk in all men

NEW YORK (Reuters Health) - Finasteride (Proscar) reduces the risk of prostate cancer in all men, regardless of their risk level for the disease, new research shows.

In the Prostate Cancer Prevention Trial, finasteride treatment cut the risk of prostate cancer by 25 percent. Whether this was because the drug prevented the cancer from forming or because it effectively treated early disease was unclear, Dr. Ian M. Thompson, from the University of Texas Health Science Center at San Antonio, and colleagues note.

The new findings, reported in the journal Urology, suggest that the drug has both effects.

In a re-analysis of data from the Prostate Cancer Prevention Trial, Thompson and co-researchers stratified 10,181 participants into five groups based on their prostate cancer risk, as determined using standard criteria.

At study entry, the men were also grouped according to PSA (prostate-specific antigen) levels, a common blood test in which increased levels may suggest the presence of prostate cancer.

Treatment with finasteride reduced the risk of prostate cancer for all five risk groups, including men with the lowest and those with the highest risk for prostate cancer.

Finasteride treatment also lowered the risk of prostate cancer regardless of the PSA level. However, the researchers found that the benefits of the drug decreased slightly as PSA levels rose.

Although this study began with the objective of evaluating the prevention versus treatment hypothesis, "the results speak to the clinical use of finasteride for reducing a man's risk of a prostate cancer diagnosis," the investigators conclude.

Thompson's team stresses that "all men undergoing PSA screening should be informed of the potential for finasteride to reduce their risk of prostate cancer."

SOURCE: Urology, May 2008.