Myeloprotective effect of early primary granulocyte-colony stimulating factor during intensified 5-fluorouracil, epirubicin and cyclophosphamide (120FEC) chemotherapy for advanced breast cancer.

AIMS AND BACKGROUND: The neutropenia induced by six courses of an intensified FEC regimen is expected to be checked by early primary administration of G-CSF which is stopped eight days before the next chemotherapy course. Less information is available about megakaryocytic and erythroid toxicity over six courses.

METHODS AND STUDY DESIGN: Sixty-six consecutive patients with metastatic breast cancer completed six courses of a randomized treatment with two FEC regimens administered every 21 days, in which 600 mg/m2 of cyclophosphamide and 5-FUwas associated with 60 or 120 mg/m2 of epirubicin (60FEC, 35 patients, vs 120FEC, 31 patients). 120FEC was supported by early primary G-CSF (days 4 to 13). Blood counts were obtained seven times during each course.

RESULTS: The non-hematologic toxicity over 364 courses was similar in 60FEC and 120FEC. No cumulative hematologic toxicity was observed for white blood cells (WBC) and platelets (PLT), while for hemoglobin (Hb) a somewhat higher cumulative toxicity was observed with 120FEC than with 60FEC. WBC, PLT and Hb grade III-IV toxicity occurred in 40.1% and 45.6% (P=ns), in 23.1% and 0.8% (P <.0001) and in 15.6% and 3.0% (P <.005) of the two regimens, respectively. There were no febrile or hemorrhagic episodes. The epirubicin relative dose intensity delivered was 1.95 in 120FEC with respect to 60FEC.

CONCLUSIONS: Our G-CSF schedule permitted to deliver six courses of 120FEC without any clinically relevant side effects. Grade III-IV leukopenia was similar with 120FEC and 60FEC, while grade III-IV thrombocytopenia and anemia occurred more often with 120FEC than with 60FEC.