Phase II study of megestrol acetate for metastatic carcinoma of the prostate

Forty-three males with recurrent and metastatic cancer of the prostate were treated with megestrol acetate (160 mg/day orally) after having failed first-line hormonal treatment (orchiectomy or diethylstilboestrol). Thirty-seven patients were evaluated objectively for response, 28 of whom received the drug for more than 6 weeks. One patient had a partial response (National Prostatic Cancer Project criteria) and seven had stable disease. Toxicity was usually mild, although five patients developed a transient rise in liver enzymes and one patient had a grand mal fit. Three patients showed evidence of tumour "flare". Megestrol acetate has only limited efficacy in patients previously treated for prostatic cancer by hormonal manipulation.