Randomized, controlled, multicenter phase III trial of standard-dose fluorouracil-epirubicin-cyclophosphamide (FEC), compared with time-intensive FEC (FEC-G) and mitoxantrone-methotrexate-mitomycin C (MMM-G) in metastatic breast carcinoma

The purpose of this multicenter phase III trial was to assess the impact of a time-intensification of FEC (fluorouracil, epirubicin, cyclophosphamide) and MMM (mitoxantrone, methotrexate, mitomycin C) regimens, supported by lenograstim (G-CSF) on the objective response rate, time to progression and survival of patients with chemotherapy-naive metastatic breast cancer (mbc). Women with mbc were randomized to receive as first-line chemotherapy either standard-dose FEC (all doses in mg/m(2)): arm A (500, 75, 500 every 21 days), or time-intensified FEC-G: arm B (500, 75, 500 every 14 days), or time-intensified MMM-G: arm C (mitoxantrone 10, methotrexate 35 every 14 days and mitomycin C 10 every 28 days), both with support of lenograstim (G-CSF 150 mug/m(2)/day sc for 10 days). All study treatments were administered for six cycles. Eligible female patients were in the 3170 year range with histologically proven mbc, and measurable or evaluable disease. An intent-to-treat analysis was performed. The overall response rate (CR + PR, intent-to-treat analysis) was significantly improved in the time-intensified FEC-G regimen (69%) in comparison with standard-dose FEC (41%), p=0.002. Time-intensified MMM-G (51%) did not lead to a significant improvement in the response rate. The percentage of complete responses was significantly higher in the FEC-G arm as compared to standard-dose FEC (17% vs. 4.7%; p=0.002). The median duration was longer in the intensified-dose arms without, however, achieving a statistically significant improvement. The median time to progression (TTP), and the median survival time did not differ between the three treatment arms. Grade 3-4 leukopenia was significantly higher (p<0.001) in the standard FEC regimen-treated patients. Thrombocytopenia was significantly higher (p<0.001) in both intensified regimens. Alopecia and mucositis were significantly more frequent in both anthracycline-containing regimens (p=0.003). Other hematological and non hematological toxicities were similar in the 3 treatment arms. The increase of dose-intensity of both FEC and MMM regimens improved activity, but not efficacy as compared to standard FEC regimen in our group of chemotherapy-naive, metastatic breast cancer patients.