Sequential versus alternating regimens in the treatment of advanced breast cancer. Argentine Breast Cancer Cooperative Group.

With the object of proving whether sequential or alternate forms of chemotherapy would be advantageous one over the other in treating advanced breast cancer and with the purpose of evaluating two different anthracyclines at equimolecular doses in the above-mentioned alternating regimens, 250 patients who had received no prior chemo- or hormonotherapy were entered in a prospective randomized trial. Group A was administered 4-epiadriamycin and cyclophosphamide for 8 courses, followed by 6 cycles of CMF, and medroxyprogesterone acetate (MPA) from the beginning of therapy until progression. In group B, adriamycin + cyclophosphamide were alternated with CMF every two courses until 14 cycles were completed. Group C received 4'-epiadriamycin + cyclophosphamide alternated with CMF for 14 courses. In groups B and C, MPA was administered as in group A. Two hundred and twenty-four patients were evaluated. CR + PR were observed in 55.8% of group A, 43.4% of group B, and 46.4% of group C. Median duration of responses was 16 months (m) in group A, 13 m in group B and 20 m in group C, and median survival (CR + PR) was 16.5 m in group A, 16 m in group B and 24 m in group C. There were no statistically significant differences among the three groups in terms of response rate, duration of response and survival; furthermore, toxicity was moderate in all groups. At equimolecular doses there were no differences between adriamycin and epirubicin in the alternating schedules.