Benefit of taxanes as adjuvant chemotherapy for early breast cancer - Pooled analysis of 15,500 patients

BACKGROUND. The magnitude of the survival benefit of taxanes as adjuvant chemotherapy for early breast cancer is still unclear. A pooled analysis of Phase III trials was performed to assess the advantages that adjuvant taxane chemotherapy has over standard chemotherapy. METHODS. All Phase III trials were considered eligible. A pooled analysis was accomplished and event-based relative risk ratios (RR) with 95% confidence intervals (95% Cl) were derived. The significant differences in disease-free survival (DFS) and overall survival (OS) were explored. Magnitude outcome measures were absolute benefits and the number of patients needed to treat. A heterogeneity test was applied as well. A sensitivity analysis in 6 subpopulations was also performed. RESULTS. Nine trials designed to assess if paclitaxel or docetaxel improve survival (15,598 patients) were gathered. One of the 9 trials did not report OS results. Significant differences in favor of taxanes were seen in DFS in the overall (RR: 0.86; 95% Cl, 0.81-0.90 [P <.00001]) and lymph node-positive population (RR: 0.84; 95% Cl, 0.79-0.89 [P <.0001]), and in OS in the overall (RR: 0.87; 95% Cl, 0.81-0.83 [P <.0001]) and lymph node-positive population (RR: 0.84; 95% Cl, 0.77-0.92 [P <.0001]). The absolute benefits in DFS and OS in favor of taxanes ranged from 3.3% to 4.6% and from 2.0% to 2.8%, respectively. CONCLUSIONS. Considering all the available Phase III trials, taxane-based adjuvant chemotherapy for early breast cancer seems to add a significant benefit in both DFS and OS over standard chemotherapy. The lack of significant heterogeneity in the sensitivity analysis underscores the homogeneous effect across all trials.