Raloxifene, Drug Used For Osteoporosis, Shown To Potentially Benefit Prostate Cancer Patients

Prostate cancer is the leading cause of cancer and the second leading cause of cancer-related death among men living in the United States. Approximately one in six men will be diagnosed with prostate cancer during his lifetime. "We undertook this study because we desperately need new therapies for patients with advanced prostate cancer," said David B. Agus, M.D., research director of the Louis Warschaw Prostate Cancer Center at Cedars-Sinai and principal investigator of the study.

Since Raloxifene is a drug already on the market, researchers were able to move directly into a Phase II clinical trial. They identified the presence of the beta isoform of the estrogen receptor in prostate cancer tissue samples, then moved directly into studies of animals with human prostate cancer, and then onto human clinical trials. The entire process took only 2-3 years.

"It used to be that to show effectiveness through research studies, cancer drugs needed to shrink tumors by 50 percent," Agus said. "Now, the new way of thinking about the effectiveness of cancer drugs is whether they can slow cancer's growth, which ultimately may significantly benefit patients."

Through the study, patients were given a daily oral dosage of Raloxifene, and the disease and its symptoms were followed on a regular basis. Some of the patients in the clinical trial taking Raloxifene showed evidence of disease stabilization manifested by a slowing or stopping of the growth of their prostate cancer.

According to Ronald L. Shazer, M.D., primary author of the manuscript, "The outcome from the Phase II clinical trial merits further study in a randomized clinical trial to demonstrate the clinical benefit of this targeted therapy."

The study was funded by the Prostate Cancer Foundation and the Elle and Paul Stephens Family Foundation.