LOS ANGELES, Calif., Aug. 1, 1998 -- A new study by USC/Norris Cancer Center scientists raises serious questions about the potential use of the drug finasteride to prevent prostate cancer.

Scientists have theorized that finasteride, sold under the brand name Proscar and commonly used to treat benign prostate disease, might offer men a way to cut their risk of developing prostate cancer.

Yet, "it appears that finasteride may not be effective as a chemopreventive agent against prostate cancer, at least in men with high PSA levels," says Ronald K. Ross, M.D., USC professor of preventive medicine and deputy director of the USC/Norris Cancer Center.

"There may even be a subgroup of patients in whom the drug actually could be harmful," says co-author Richard J. Cote, M.D., USC associate professor of pathology and urology. Ross and Cote, along with Eila C. Skinner, M.D., USC associate professor of urology, led the study, which appears in the first August issue of the British Journal of Cancer.

Prostate cancer is the most frequently diagnosed cancer in the United States, and proves fatal for some 40,000 men each year. At present, there's no proven way to prevent the disease.

USC/Norris researchers have long led research on the role of the male hormones androgens in spurring prostate cancer growth. Ross and his colleagues first proposed that lowering levels of the androgen most active in the prostate, called dihydrotestosterone (DHT), could possibly prevent prostate cancer. Ross' team was also the first to suggest that finasteride, which lowers the levels of DHT by blocking the enzyme that converts testosterone into DHT, might prevent the formation of prostate cancer.

The National Cancer Institute (NCI) is in the midst of a large national clinical trial to determine if finasteride can reduce the incidence of prostate cancer. The seven-year NCI study has
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Contact: Eva Emerson or Brenda Maceo
eemerson@hsc.usc.edu
323-442-2830
University of Southern California
1-Aug-1998