Anthracycline and trastuzumab in breast cancer treatment

Abstract

This study was designed to evaluate the cardiac safety of the combined treatment of HER2-positive metastatic breast cancer patients with trastuzumab (Herceptin) plus epirubicin and cyclophosphamide (EC) in comparison with EC alone in HER2-negative metastatic breast cancer patients. Patients included those with metastatic breast cancer without any prior anti-HER2 treatment, anthracycline therapy, or any other chemotherapy for metastatic disease. This was a nonrandomized, prospective, dose-escalating, multicenter, open-label, phase I study in Germany. A control group of 23 patients received EC 90/600 mg/m2 3-weekly for six cycles (EC90 alone). A total of 26 HER2-positive patients were treated with trastuzumab, or H (2 mg/kg weekly after an initial loading dose of 4 mg/kg), and EC 60/600 mg/m2 3-weekly for six cycles (EC60+H); another 25 HER2-positive patients received H and EC 90/600 mg/m2 3-weekly for six cycles. Asymptomatic reductions in left ventricular ejection fraction (LVEF) of more than 10% points were detected in 12 patients (48%) treated with EC60+H and in 14 patients (56%) treated with EC90+H vs 6 patients (26%) in the EC90 alone cohort. LVEF decreases to <50% occurred in one patient in the EC60+H cohort and in two patients in the EC90+H cohort during the H monotherapy. No cardiac event occurred in the cohort with EC90 alone. The overall response rates for EC60+H and EC90+H were >60%, vs 26% for EC90 alone. The interim results of this study approve the cardiac safety of the combination of H with EC, with low risk of cardiac toxicity. The combination regimen revealed promising efficacy.