Phoenix, Arizona--Prostate cancer patients receiving radiotherapy who are at a high risk of dying of the disease have an increased survival rate if they take hormonal therapies for longer than average periods, according to a study conducted by a University of California San Francisco prostate cancer expert. Mac Roach, III, MD, UCSF associate professor of radiation oncology and medicine, will present his findings today (October 28) at the annual meeting of the American Society of Therapeutic Radiation Oncology (ASTRO).
"Our study showed a 20 percent increase in survival after eight years for high risk prostate cancer patients who continued to receive hormonal therapy in conjunction with radiotherapy compared to those who received radiotherapy alone," Roach said. "This is the first study to suggest that some prostate cancer patients may need to take hormonal therapy for as long as breast cancer patients typically do in order to reach the maximum effect of the treatment."
He noted that prostate and breast cancer are similar diseases because both are hormone dependent. In prostate cancer, the male's androgens or sex hormones, such as testosterone, act as a "catalyst" in governing the functions of the prostate and prostate cancer cells. In animal models, depleting tumors of hormones has been shown to weaken cancer cells, making them more sensitive to radiation, Roach said.
During the study, researchers found that high risk patients who received radiotherapy alone had a 34 percent chance of dying of prostate cancer after the first five years of treatment. Conversely, those who received hormonal therapy in conjunction with radiotherapy had a 19 percent chance of dying of the disease.
Roach said that prostate cancer patients frequently take hormone therapies for approximately four months. Recent American studies have administered the drug to men in clinical trials for two years, and in European studies, for three years.
In the study, 2,46
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Contact: Abby Sinnott
sinnott@itsa.ucsf.edu
415-885-7277
University of California - San Francisco
28-Oct-1998