Influence of treatment schedule on toxicity and efficacy of cyclophosphamide, epirubicin, and fluorouracil in metastatic breast cancer: a randomized trial comparing weekly and every-4-week administration.

PURPOSE To compare the effect on toxicity and efficacy of the fluorouracil 500 mg/m2, epirubicin 60 mg/m2, and cyclophosphamide 500 mg/m2 (FEC) regimen divided into 4 weekly doses with conventional every-4-week administration in metastatic breast cancer. PATIENTS AND METHODS The inclusion criteria demanded measurable or assessable metastases from breast cancer and a World Health Organization (WHO) performance index of 2 or less. One hundred seventy-three patients with metastatic breast cancer who had not been treated with anthracyclines were randomized to receive FEC once every 4 weeks or once a week. The scheduled monthly doses of the cytotoxic agents were identical in both groups. Three patients were excluded from analysis. RESULTS Hematologic toxicity, alopecia, nausea, and vomiting were significantly more severe in the group that received treatment every 4 weeks. The response rate was higher in the group that received FEC every 4 weeks than in the group treated weekly (47% v 30%, P = .02). Time to progression was significantly (P = .005) longer with every-4-week FEC treatment (median, 9.2 months v 5.4 months for weekly treatment). Patients in the group treated every 4 weeks lived significantly (P = .01) longer than patients treated weekly (median survival times, 21.2 months v 11.8 months, respectively). The actually delivered monthly dose levels and treatment duration were similar in the two groups. CONCLUSION Both efficacy and toxicity of FEC were greater when treatment was administered every 4 weeks rather than once a week, despite identical dose intensity.