Adjuvant chemotherapy for older adults with breast cancer: making the standard a standard

To date, only two prospective trials evaluating adjuvant therapy for breast cancer in older adults have been published. The second and more recent trial, Cancer and Leukemia Group B (CALGB) 49907, provides substantial evidence supporting the use of standard adjuvant chemotherapy regimens (doxorubicin-cyclophosphamide or cyclophosphamide-methotrexate-5-fluorouracil) as opposed to simplified oral regimens (capecitabine). In this trial, both the risk of relapse (hazard ratio: 2.09; 95% CI: 1.38-3.17; p < 0.001) and the risk of death (hazard ratio: 1.85; 95% CI: 1.11-3.08; p = 0.02) were significantly higher with capecitabine compared with standard chemotherapy. The current review explores both the implications and potential caveats of this innovative trial. CALGB 49907 represents a paradigm for further studies of adjuvant cancer therapy in older adults.