Decreased efficacy of cyclophosphamide, epirubicin and 5-fluorouracil in metastatic breast cancer when reducing treatment duration from 18 to 6 months.

The impact of treatment duration on survival and progression-free survival is uncertain in metastatic breast cancer. In this trial 359 patients were randomised to receive cyclophosphamide, epirubicin and 5-fluorouracil (CEF) once every 3 weeks for a maximum of 18 months or identical chemotherapy for a maximum of 6 months. Following progressive disease (PD) or severe toxicity CEF was discontinued before the scheduled maximum duration. A second series of CEF continued for a maximum of 12 months was offered to patients with PD more than 3 weeks after completing a maximum of 6 months of CEF. Both groups received tamoxifen (30 mg daily) until PD, and premenopausal patients also received ovarian irradiation. After 6 months 254 evaluable patients were unprogressive. Survival and progression-free survival were significantly longer in 127 patients continuing CEF than in 127 patients interrupting CEF at 6 months (chi 2 = 17.6, P = 0.00003 and chi 2 = 4.7, P = 0.03, respectively). The results of the second series of CEF were discouraging with only one complete response in 44 evaluable patients. In conclusion, prolonged chemotherapy for 18 months is superior to identical chemotherapy for 6 months in the treatment of metastatic breast cancer.