The Canadian experience with intensive fluorouracil, epirubicin and cyclophosphamide in patients with early stage breast cancer.

A multicentre dose-finding pilot study was conducted to determine an intensive regimen of fluorouracil (F), epirubicin (E) plus cyclophosphamide (C) [FEC] that was tolerable and acceptable to patients with node-positive operable (n = 266) or locally advanced (n = 22) breast cancer. Consecutive patients were treated with fluorouracil and epirubicin administered intravenously on days 1 and 8, in addition to cyclophosphamide orally for 14 days. Chemotherapy cycles were repeated at monthly intervals for 6 months, and dosages were increased according to a predetermined protocol. End-points were hospital admissions due to febrile neutropenia and changes in cardiac function as assessed by radionuclide angiography. The first 46 patients were treated with doses of F = 375 mg/m2, E = 50 mg/m2 and C = 75 mg/m2 (level 1), then 42 patients received F = 500 mg/m2, E = 50 mg/m2 and C = 75 mg/m2 (level 2), 69 patients received F = 500 mg/m2, E = 60 mg/m2 and C = 75 mg/m2 (level 3), and 42 patients received F = 500 mg/m2, E = 70 mg/m2 and C = 75 mg/m2 with concurrent antibiotics (level 4). Rates of febrile neutropenia were 8.7% (level 1), 7.1% (level 2), 18.8% (level 3), and 31% (level 4) [p = 0.002]. Accrual to level 4 was discontinued according to study protocol and a further 89 patients were recruited at level 3 dosages with antibiotic prophylaxis (level 3a), resulting in a 5.6% rate of febrile neutropenia. The difference in febrile neutropenia rates between dosage levels 3 and 3a was statistically significant (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)