SUNDAY, Dec. 6, 2009 (HealthDay News) -- Hot flashes caused by androgen suppression therapy for prostate cancer are best controlled by the hormonal treatments cyproterone acetate and medroxyprogesterone acetate, according to a new study.
Androgen suppression is considered the gold standard treatment for advanced prostate cancer, but about 80 percent of patients undergoing the treatment experience hot flashes. A number of hormonal and non-hormonal drugs are used to treat the hot flashes, but no direct comparisons of the drugs have been made in clinical trials.
The new study included 311 prostate cancer patients in France undergoing androgen suppression therapy. To treat their hot flashes, they received either the non-hormonal drug venlafaxine (102 men), or one of two hormonal drugs -- cyproterone acetate (101 men) or medroxyprogesterone acetate (108 men). The patients were assessed at weeks four, eight and 12 and asked to complete a questionnaire about the frequency and severity of their hot flashes for the week before each assessment.
The researchers found that all three drugs reduced the occurrence of hot flashes, but the hormonal drugs were much more effective at reducing them over all time periods.
After receiving treatment for four weeks, 219 patients (nearly 71 percent) reported an improvement of at least 50 percent in their hot flash scores, and 70 patients (nearly 23 percent) said they no longer had hot flashes. By the fourth week, hot flash scores were reduced by 47.2 percent for the venlafaxine group, 83.7 percent for the medroxyprogesterone acetate group and 94.5 percent for the cyproterone acetate group.
Among men receiving gonadotrophin-releasing hormone analogue therapy for prostate cancer, cyproterone acetate and medroxyprogesterone acetate are more effective at 12 weeks for treating hot flashes, the researchers concluded. However, "as cyproterone is a recognized treatment in prostate cancer, and its use could interfere with hormone therapy, medroxyprogesterone should be the standard treatment," they wrote.
The study will be published online Dec. 7 in The Lancet Oncology.
The American Urological Association has more about androgen suppression therapy for prostate cancer.