Docetaxel has not been compared with vinorelbine as adjuvant treatment of early breast cancer. Efficacy and long-term safety of a short course of adjuvant trastuzumab administered concomitantly with chemotherapy for human epidermal growth factor receptor 2 (HER2) -positive cancer are unknown.

One thousand ten women with axillary node-positive or high-risk node-negative breast cancer were randomly assigned to receive three cycles of docetaxel or vinorelbine, followed in both groups by three cycles of fluorouracil, epirubicin, and cyclophosphamide (FEC). Women with HER2-positive cancer (n = 232) were further assigned to either receive or not receive trastuzumab for 9 weeks with docetaxel or vinorelbine. The median follow-up time was 62 months after random assignment.

Women assigned to docetaxel had better distant disease-free survival (DDFS) than those assigned to vinorelbine (hazard ratio [HR] = 0.66; 95% CI, 0.49 to 0.91; P = .010). In the subgroup of HER2-positive disease, patients treated with trastuzumab tended to have better DDFS than those treated with chemotherapy only (HR = 0.65; 95% CI, 0.38 to 1.12; P = .12; with adjustment for presence of axillary nodal metastases, HR = 0.57; P = .047). In exploratory analyses, docetaxel, trastuzumab, and FEC improved DDFS compared with docetaxel plus FEC (HR = 0.32; P = .029) and vinorelbine, trastuzumab, and FEC (HR = 0.31; P = .020). The median left ventricular ejection fraction of trastuzumab-treated patients remained unaltered during the 5-year follow-up; only one woman treated with trastuzumab was diagnosed with a heart failure.

Adjuvant treatment with docetaxel improves DDFS compared with vinorelbine. A brief course of trastuzumab administered concomitantly with docetaxel is safe and effective and warrants further evaluation.