Adjuvant chemotherapy plus tamoxifen compared with tamoxifen alone for postmenopausal breast cancer: meta-analysis of quality-adjusted survival.
Gelber RD., Cole BF., Goldhirsch A., Rose C., Fisher B., Osborne CK., Boccardo F., Gray R., Gordon NH., Bengtsson NO., Sevelda P.
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 chemoendocrine therapy did not provide more quality-adjusted survival time than tamoxifen alone for women aged 50 years or older with node-positive breast cancer. Better selection and administration of chemotherapy regimen, different scheduling of chemotherapy and tamoxifen, and appropriate use of patient and tumour characteristics may increase the therapeutic advantage of the combination.