[Therapeutic effects of medroxyprogesterone acetate in recurrent or advanced breast cancer]

Medroxyprogesterone acetate (MPA) was given to 25 cases of recurrent or advanced breast cancer in consecutive oral doses of 1,200 mg/day to evaluate its efficacy. Results in 22 evaluable cases were: CR in 5, PR in 6, NC in 3 and PD in 8 cases, response rate being 50% (11/22). Pretreatment of 11 cases with pharmacological endocrine therapy was effective in 7 cases, 4 of which were led to remission by MPA treatment. In 4 cases which did not respond to the pretreatment, 2 showed response to MPA. This suggests the appearance of a new method of treatment in addition to conventional endocrine therapy. Response rate of MPA in ER-positive cases was 60% (6/10); for ER-negative cases, MPA had no effect in the 3 cases studied. Response rate in postmenopausal patients was 39% (7/18). It is noticeable that MPA was effective in all of 4 premenopausal patients (CR1, PR3). A striking increase in weight was controlled after a full explanation before the study by a diet consisting mainly of staple food.