High Dose Medroxyprogesterone Acetate (MPA) Treatment in Metastatic Carcinoma of the Breast: A Dose-Response Evaluation

Abstract

The results of a controlled clinical trial that used high doses of medroxyprogesterone acetate (MPA) in the treatment of metastatic breast cancer are reported. Two treatment regimens were used: regimen A, 500 mg daily with a total dose of 30 g; regimen B, 1,000 mg daily with a total dose of 60 g. The overall response rates were similar, with no statistically significant difference between the two treated groups. Regimen A (lower dosage group) reached a remission rate of 44%, whereas regimen B (higher dosage group) had a remission rate of 41%. The mean duration of response was 8 months with regimen A and 9 months with regimen B. The advantages of the lower dosage regimen as opposed to the higher dosage regimen of MPA in the treatment of advanced breast cancer are discussed.