Combined cytotoxic and endocrine therapy in postmenopausal patients with advanced breast cancer. A randomized EORTC study of CMF vs CMF + tamoxifen.

Two hundred and sixty-three patients with advanced measurable breast cancer were randomized to receive cyclophosphamide, methotrexate and 5-fluorouracil (CMF) or CMF + tamoxifen (T). Each cycle of CMF (C, 100 mg/m2 p.o. days 1-14, M, 40 mg/m2 i.v. days 1 and 8, F, 600 mg/m2 i.v. days 1 and 8) was repeated every 4 weeks. Tamoxifen, 20 mg twice daily, was given continuously. The treatment results as assessed by external reviewing were as follows in the CMF and CMF + T groups, respectively: PD 24 and 10%, NC 27 and 15%, PR 29 and 44%, CR 20 and 31%. The difference between response (CR + PR) rates is highly significant (P = 0.0001). Derived from life-table analysis, the median duration of remission was 12 months in the CMF-treated group and 18 months in patients treated with CMF + T (P = 0.04). Median duration of survival was 19 and 24 months, respectively (P = 0.12), but in the group of responders CMF + T was significantly superior to CMF (32 months vs 21 months, P = 0.03). The addition of T was of benefit to all subgroups but the difference only reached statistical significance in patients with the dominant site of disease in viscera, in patients with a Karnofsky index of 100 and in patients of more than 60 years of age. The amount of CMF given was identical in two groups with a trend for a decrease in dose with increasing age. No relation between response rate and amount of dose given was observed. In conclusion, the addition of T to CMF improves the therapeutic results in patients with advanced breast cancer although the superiority of the combined treatment is statistically significant only in some subsets of patients.