Effect of renal function (RF) on outcomes in the adjuvant treatment of older women with breast cancer (>65 years): CALGB/CTSU 49907 (CC) ancillary data study.

9515 Background: CC 49907 showed superiority of standard therapy (cyclophosphamide/doxorubicin [AC] or cyclophosphamide/methotrexate/5-fluorouracil [CMF]) over capecitabine[C]. Dose adjustments made for renal insufficiency (RI) for methotrexate and C; ideal body weight used. Purpose was to analyze the relationship between RF at baseline and 5 endpoints: toxicity, dose modification, therapy completion, relapse-free survival [RFS] and overall survival [OS]. Methods: Pre-treatment RF was calculated (Cockcroft-Gault). Endpoints assessed by regimen. RF was tested as a dichotomous and continuous variable of stages 1,2 vs. 3,4 kidney disease (National Kidney Foundation). Logistic regression modeled the relationship between renal stage and the first three endpoints of toxicity, dose modification and therapy completion. Toxicity divided by hematologic or not. The relationship of RFS and OS with RF was assessed with the logrank test and as a continuous variable with Wald chi square. Results: 619 patients; incidence...