Adjuvant chemotherapy plus tamoxifen compared with tamoxifen alone for postmenopausal breast cancer: Meta-analysis of quality-adjusted survival

Background Adjuvant tamoxifen for early breast cancer provides an improvement in relapse-free (RFS) and overall survival (OS), especially for older women. We carried out a meta-analysis to find out whether the benefit of adding chemotherapy to tamoxifen outweighs its costs in terms of toxic effects for postmenopausal patients. Methods The meta-analysis of quality-adjusted survival was based on data from 3920 patients aged 50 years or older with node-positive breast cancer randomly assigned in nine trials that compared combination chemotherapy plus tamoxifen with tamoxifen alone. The nine trials were included in the worldwide overview conducted by the early breast. cancer trialists' collaborative group (EBCTCG). The quality-adjusted time without symptoms or toxicity (Q-TWiST) method was used to provide treatment comparisons incorporating differences in quality of life associated with subjective toxic effects of treatment and symptoms of disease relapse. Findings Within 7 years of follow-up the modest benefit of increased RFS and OS for patients who received chemotherapy just balanced the costs in terms of acute toxic side-effects. Chemotherapy-treated patients gained an average of 5 . 4 months of RFS and 2 months of OS (neither statistically significant), but had to receive cytotoxic treatment for between 2 and 24 months to achieve these gains. No values of preference weights for time spent undergoing chemotherapy and time after relapse gave significantly more Q-TWiST with chemotherapy plus tamoxifen than with tamoxifen alone. Interpretation Within 7 years of follow-up, adjuvant significant advantage in relapse-free survival, but the effect on overall survival was not significant. The question of whether the observed benefit for chemotherapy outweighs the costs in terms of toxic effects demands an answer before the regimen is used for all postmenopausal patients who require adjuvant systemic therapy. Our evaluation of chemotherapy effectiveness in postmenopausal patients was based on a meta-analysis of quality-adjusted survival. We analysed data from all trials on combination chemotherapy plus tamoxifen versus tamoxifen alone included in the EBCTCG overview update. Treatment effects were estimated exclusively for patients aged 50 years or older. We provided an additional type of analysis that incorproated features of quality of life into the treatment comparison.