In 1984, the International Collaborative Cancer Group (ICCG) started a randomised trial comparing adjuvant treatment with cyclophosphamide 100 mg/m2 orally on days 1 to 14, methotrexate 40 mg/m2 intravenously on days 1 and 8 plus fluorouracil 600 mg/m2 intravenously on days 1 and 8 every 4 weeks for 6 cycles (CMF) vs fluorouracil 600 mg/m2, epirubicin 50 mg/m2 and cyclophosphamide 600 mg/m2 (FEC), all given intravenously on day 1 for 8 cycles at 3-week intervals in premenopausal patients with node-positive breast cancer. However, a large French institution that joined the ICCG shortly after the trial was initiated utilised different schedules of both CMF and FEC. Because different dose intensities were also employed, particularly of FEC, both patient groups, the French and non-French, will be analysed separately. A total of 761 patients were randomised as of March 1992. Patients were well balanced for prognostic factors. The median follow-up is now 3.5 years. Preliminary data have previously been reported in abstract form. Final data will be presented pending further follow-up.