Data Show Dutasteride Reduces Prostate Cancer Diagnosis in Men with Increased Risk

Newswise — Dutasteride (Avodart), a commonly prescribed drug to treat benign prostatic hyperplasia, has been shown to lower the risk of prostate cancer by 23 percent in men with an increased risk of the disease, according to results of an international clinical trial presented today at the American Urological Association (AUA) Annual Meeting in Chicago. Data from the REDUCE Trial is being presented to members during the plenary session, and lead investigator Gerald Andriole, MD, of Washington University School of Medicine in St. Louis, will hold a special session for interested media at 12:15 p.m. in the AUA Press Suite.

The REDUCE trial is the first to examine chemoprevention for prostate cancer in men at increased risk for the disease. The trial involved 8,200 men ages 50 " 75 who were randomly assigned to receive a placebo or a daily 0.5 mg dose of dutasteride. Men in the study had elevated PSA levels (2.5 " 10 ng/ml) indicating that they were at increased risk of prostate cancer. They had undergone biopsies that found no evidence of cancer within six months prior to enrolling in the trial. Therefore these men either did not have prostate cancer or possibly had microscopic tumors that were too small to be detected by the pre-study biopsy.

The investigators performed scheduled biopsies on the men two years after they enrolled in the study and again after four years. After two years, prostate cancer was found in 17.2 percent of the men who took a placebo, compared with 13.4 percent who took dutasteride. After four years, prostate cancer was diagnosed in another 11.8 percent of men who received a placebo and 9.1 percent who received dutasteride.

"In these men, the most likely explanation is that dutasteride worked by shrinking tumors and/or slowing their growth, thereby making them less likely to be detected by a biopsy," Dr. Andriole said. "This drug has the potential to offer many thousands of men a way to reduce their risk of being diagnosed with prostate cancer and, as a result, more men could avoid treatment for prostate cancer and the cost and unwanted side effects associated with treatment."

The investigators found that there was no greater risk for the men who did develop prostate cancer to have aggressive tumors. This outcome was closely watched because an earlier trial of a similar BPH drug " finasteride (Proscar) " produced controversial results with regard to the risk of more aggressive tumors in those men who developed prostate cancer while on finasteride. An initial analysis of the finasteride data suggested that there was an increased risk for men to have prostate cancer with higher Gleason scores but a later analysis suggested that there is probably no greater risk for these men to develop higher grade prostate cancer. Over the course of the current study, 6.8 percent of men in the placebo group and 6.7 percent of men in the dutasteride group were found to have aggressive, high-grade tumors, defined as a Gleason score of 7 " 10.

"We are very encouraged by this finding," Dr. Andriole says. "Clearly, the data show dutasteride did not lead to more high-grade tumors, even though they would have been easier to detect in the dutasteride-treated men due to their smaller prostates."

The REDUCE (Reduction by Dutasteride of Prostate Cancer Events) trial was conducted at 250 sites in 42 countries around the world. The study was funded by GlaxoSmithKline. Dr. Andriole is chairman of the REDUCE steering committee and a consultant for the company.

For more information about this presentation, please contact AUA Communications Manager Wendy Waldsachs Isett at 410-977-4770. Dial-in information for the April 27 press conference is available for those reporters unable to attend the session in person.

About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the American Urological Association is the pre-eminent professional organization for urologists, with more than 16,000 members throughout the world. An educational nonprofit organization, the AUA pursues its mission of fostering the highest standards of urologic care by carrying out a wide variety of programs for members and their patients.