Megestrol acetate in the treatment of advanced post-menopausal breast cancer.

The effect of megestrol acetate 160 mg daily was studied in 49 previously treated post-menopausal patients with advanced carcinoma of the breast. An overall response of 31% was obtained with 1 complete and 14 partial remissions, chiefly in soft tissue and bone. The median duration of response was in excess of 10 months. Toxicity was minimal and the only notable side effect was mild weight gain without fluid retention. Megestrol acetate is safe and well tolerated, with useful activity in the palliation of advanced breast cancer.