Phase III Trial of Epirubicin Plus Paclitaxel Compared With Epirubicin Plus Cyclophosphamide As First-Line Chemotherapy for Metastatic Breast Cancer: United Kingdom National Cancer Research Institute Trial AB01

Abstract

To compare the effectiveness and tolerability of epirubicin and paclitaxel (EP) with epirubicin and cyclophosphamide (EC) as first-line chemotherapy for metastatic breast cancer (MBC). Patients previously untreated with chemotherapy (except for adjuvant therapy) were randomly assigned to receive either EP (epirubicin 75 mg/m2 and paclitaxel 200 mg/m2) or EC (epirubicin 75 mg/m2 and cyclophosphamide 600 mg/m2) administered intravenously every 3 weeks for a maximum of six cycles. The primary outcome was progression-free survival; secondary outcome measures were overall survival, response rates, and toxicity. Between 1996 and 1999, 705 patients (353 EP patients and 352 EC patients) underwent random assignment. Patient characteristics were well matched between the two groups, and 71% of patients received six cycles of treatment. Objective response rates were 65% for the EP group and 55% for the EC group (P = .015). At the time of analysis, 641 patients (91%) had died. Median progression-free survival time was 7.0 months for the EP group and 7.1 months for the EC group (hazard ratio = 1.07; 95% CI, 0.92 to 1.24; P = .41), and median overall survival time was 13 months for the EP group and 14 months for the EC group (hazard ratio = 1.02; 95% CI, 0.87 to 1.19; P = .8). EP patients, compared with EC patients, had more grade 3 and 4 mucositis (6% v 2%, respectively; P = .0006) and grade 3 and 4 neurotoxicity (5% v 1%, respectively; P < .0001). In terms of progression-free survival and overall survival, there was no evidence of a difference between EP and EC. The data demonstrate no additional advantage to using EP instead of EC as first-line chemotherapy for MBC in taxane-naïve patients.