[A controlled study with medroxyprogesterone acetate (MPA) alone or in combination with cyclophosphamide (CPA) in the treatment of advanced or recurrent breast cancer unresponsive to other therapies. Osaka Study Group for the Treatment of Breast Cancer].

Forty-eight patients with advanced or recurrent breast cancer unresponsive to other therapies were treated orally with medroxyprogesterone acetate (MPA) 1,200 mg/day alone (Group A: 28 patients) or in combination with cyclophosphamide (CPA) 100 mg/day (Group B: 20 patients). Either complete response (CR) or partial response (PR) was obtained in eight (28.6%) patients of Group A and PR in five (25.0%) of Group B. The median duration of the response was 5.3 months in Group A and 4.4 months in Group B. Despite the expected better result of the combined chemo-endocrine therapy for Group B, there were no statistical difference in usefulness between the two regimens. No severe adverse reactions were observed in this study. We conclude that MPA alone is useful for treatment of patients with advanced or recurrent breast cancer unresponsive to other therapies.