ADJUVANT CHEMOTHERAPY PLUS TAMOXIFEN COMPARED WITH TAMOXIFEN ALONE FOR POSTMENOPAUSAL BREAST-CANCER - METAANALYSIS OF QUALITY-ADJUSTED SURVIVAL

Background Adjuvant tamoxifen for early breast cancer provides an impr ovement in relapse-free (RFS) and overall survival (OS), especially fo r older women. We carried out a meta-analysis to find out whether the benefit of adding chemotherapy to tamoxifen outweighs its costs in ter ms of toxic effects for postmenopausal patients. Methods The meta-anal ysis of quality-adjusted survival was based on data from 3920 patients aged 50 years or older with node-positive breast cancer randomly assi gned in nine trials that compared combination chemotherapy plus tamoxi fen with tamoxifen alone. The nine trials were included in the worldwi de overview conducted by the early breast. cancer trialists' collabora tive group (EBCTCG). The quality-adjusted time without symptoms or tox icity (Q-TWiST) method was used to provide treatment comparisons incor porating differences in quality of life associated with subjective tox ic effects of treatment and symptoms of disease relapse. Findings With in 7 years of follow-up the modest benefit of increased RFS and OS for patients who received chemotherapy just balanced the costs in terms o f acute toxic side-effects. Chemotherapy-treated patients gained an av erage of 5 . 4 months of RFS and 2 months of OS (neither statistically significant), but had to receive cytotoxic treatment for between 2 an d 24 months to achieve these gains. No values of preference weights fo r time spent undergoing chemotherapy and time after relapse gave signi ficantly more Q-TWiST with chemotherapy plus tamoxifen than with tamox ifen alone. Interpretation Within 7 years of follow-up, adjuvant signi ficant advantage in relapse-free survival, but the effect on overall s urvival was not significant. The question of whether the observed bene fit for chemotherapy outweighs the costs in terms of toxic effects dem ands an answer before the regimen is used for all postmenopausal patie nts who require adjuvant systemic therapy. Our evaluation of chemother apy effectiveness in postmenopausal patients was based on a meta-analy sis of quality-adjusted survival. We analysed data from all trials on combination chemotherapy plus tamoxifen versus tamoxifen alone include d in the EBCTCG overview update. Treatment effects were estimated excl usively for patients aged 50 years or older. We provided an additional type of analysis that incorproated features of quality of life into t he treatment comparison.