Megestrol acetate used as primary hormonal therapy in stage D prostatic cancer.

The majority of patients with advanced prostatic cancer respond either to castration or estrogen therapy. In an attempt to identify an alternative hormonal therapy, 25 symptomatic stage D prostate cancer patients were treated with megestrol acetate as initial hormonal therapy. Thirty-three patients were evaluable for response as defined by the National Prostatic Cancer Project criteria. Partial remission was observed in 11 patients and stable disease in 5, with an overall response rate of 70%. The projected median duration of response and survival were 10 and 20 months, respectively. Weight gain was common, but only two patients showed evidence of fluid retention. Gynecomastia, thromboembolic episodes, and gastrointestinal side effects were not observed in this group of patients, though two patients had increased pain shortly after therapy was initiated. Thus, in advanced prostatic cancer, megestrol acetate is effective primary therapy with minimal side effects.