A possible new approach to the treatment of metastatic breast cancer: massive doses of medroxyprogesterone acetate.

The results obtained with a new hormone therapy using medroxyprogesterone acetate (MAP) in previously untested single and total doses in the treatment of advanced breast cancer are reported. Fifty-two postmenopausal patients were treated with an average total dose of 40 g of MAP for a period of 30 days. Nineteen of 44 patients (43%) had complete or partial remission, while the disease remained unchanged in nine of 44 patients (20%). Disease progression occurred in 12 of 44 patients (27%). Partial or complete remission occurred in 12 of 18 (67%) and four of six (67%) of the patients with dominant osseous and soft tissue metastases respectively. Three of ten (16%) of those with visceral metastases had remission. The average duration of remission was 7 months. Average survival times were 15.5 months for patients with remission, 8 months for those with no change, and 2.5 months for those with disease progression. From a subjective standpoint, pain was reduced significantly or disappeared in 34 of 36 patients (94%); this was also the case with respect to dyspnea (13 of 16 patients [81%]), anorexia (24 of 29 [83%]), asthenia (28 of 35 [80%]), and walking impairment (15 of 24 [63%]). When relapse occurred, patients previously treated with massive doses of MAP received further treatment with higher doses of MAP; four of 22 (18%) of the patients attained partial remission once again. Positive effects were also seen in subjective performance status, body weight, and EKG. We also describe the new clinical and toxicologic features of this treatment.