Docetaxel-containing adjuvant chemotherapy in patients with early stage breast cancer. Consistency of effect independent of nodal and biomarker status: a meta-analysis of 14 randomized clinical trials

The benefit of taxanes in the adjuvant setting for node-negative (N0) early breast cancer (EBC) has not yet been established. We conducted a meta-analysis of randomized adjuvant trials comparing docetaxel-containing versus non-taxane-containing regimens. The purpose of this study was to determine whether the incorporation of docetaxel improves disease-free survival (DFS) and overall survival (OS) in early stage breast cancer. Studies were retrieved by searching major databases and the proceedings of leading breast cancer conferences. We extracted hazard ratios (HRs) and 95% confidence intervals (CIs) for DFS and OS and obtained pooled estimates using an inverse-variance model. Fourteen randomized phase III studies were included (25,067 patients). The pooled HR estimate was 0.84 (95% CI 0.78-0.89; P < 0.001) favoring docetaxel for DFS and 0.86 (0.78-0.94; P < 0.001) for OS. In N0 patients (4,274 patients), the pooled HR estimate for DFS was 0.86 (0.73-1.00; P = 0.05). The HR for OS was equal to 1 (0.75-1.34). The improvement in DFS with docetaxel-containing regimens was observed across all subgroups (age, under or over 50; number of involved nodes; hormone receptor or HER2 status (including triple negative status), or administration schedule (sequential or concomitant). The addition of docetaxel to a non-taxane-containing regimen improves DFS and OS in high risk EBC patients. The benefit in DFS was seen across all subgroups regardless of nodal status, age, hormone receptor or HER2 status (including triple negative status), or administration schedule.