Adjuvant Taxanes in Breast Cancer: A Critical Re-appraisal

Purpose: Several studies have reported a positive impact for taxanes in adjuvant breast cancer (BC) treatment in terms of reduced recurrence and mortality. However the impact of the magnitude on overall survival (OS) remains partially controversial. Methods: We examined the impact of taxane-containing adjuvant therapy for patients with early BC on OS, based on the number of deaths and on the calculated number of patients who need to be treated with taxanes to avoid one death (NNT). We classified patients in three different groups according to whether taxanes were administered concurrently or sequentially, and whether all treatment arms had the same or different duration. Results: 1) Taxanes in combination therapy: 8258 patients (4373 with taxanes and 3885 without taxanes), with 723 OS events. Overall survival for taxane-treated patients was 92.7% versus 89.6% for patients not receiving taxanes. NNT was 33. 2) Sequential treatment of unequal duration in the treatment arms: 14,228 patients (7970 with taxanes and 6256 without). Overall survival in taxane-treated patients was 86% compared with 83.2% for patients not receiving taxanes. NNT was 44. 3) Sequential treatment and similar duration in treatment arms: 9511 women (5093 with taxanes and 4418 without). Overall survival in patients treated with taxanes was 87% versus 85% in patients not receiving taxanes. NNT was 50. When the results of all these trials were considered together, the NNT stands at 43 patients. Conclusion: Taxanes afford a modest increase in overall survival in BC patients regardless of how they are given. Translational trials may well help to improve patient selection in the future.