Oral medroxyprogesterone in the treatment of metastatic breast cancer.

In 47 postmenopausal women with evaluable breast cancer, oral medroxyprogesterone acetate (MPA) was given at a daily dose level of 400 mg. Patients with negative estrogen receptors, poor performance status, or nonresponse to previous endocrine therapy were excluded from this study. There were 25 (53%) responders to this agent. Periods of remission ranged from 5-26 months with a median of 10 and a mean of 12+ months. Higher rates of response were noted in women over 50 years of age, in patients with osseous metastasis, and in patients with a longer disease-free interval. Adverse effects included weight gain, Cushingoid appearance, skin rash, and vaginal discharge. In this selected group of patients, oral medroxyprogesterone at a dose level of 400 mg/day appeared to provide a significant frequency of tumor response.