Morganstern, Daniel

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 of stage 3/4 RI(<60 ml/min) was: CMF=72%; AC=64%; C=75%. With AC the incidence of toxicity differed by renal function. 31% of patients with poorer function >grade 3 non-hematologic toxicity vs. 14% with better function(p=0.011). There was a suggestion of effect of RF on OS and RFS for C-treated patients. RF was not associated with dose modification, premature therapy termination, RFS or OS for the CMF-treated patients. Conclusions: 1) AC: declining RF was associated with increased non-hematologic toxicity. 2)Patients with RI who received dose modifications were not at increased risk for complications in comparison to those who did not have renal insufficiency and received full dose. 3)Declining RF did not affect therapy completion. 4)C: suggestion that worse RF was related to poorer RFS or OS. 5)Exclusion of patients from clinical trials with RI based on concern of excessive hematologic toxicity may not be justified with appropriate modification. 6)Results should be considered in the design of clinical trials for older patients.

Purpose CALGB 49907 showed the superiority of standard therapy, which included either cyclophosphamide/doxorubicin (AC) or cyclophosphamide/methotrexate/fluorouracil over single-agent capecitabine in the treatment of patients age ≥ 65 with early-stage breast cancer. The treatment allowed dosing adjustments of methotrexate and capecitabine for pretreatment renal function. The purpose of the current analysis was to assess the relationship between pretreatment renal function and five end points: toxicity, dose modification, therapy completion, relapse-free survival, and overall survival. Methods Pretreatment renal function was defined as creatinine clearance (CrCl) using the Cockcroft-Gault equation. Multivariable logistic and proportional hazards regression were used to model separately for each regimen the relationship between CrCl and the first three binary end points and the last two time-to-event end points, respectively, after adjusting for variables of prognostic importance. Results Six hundred nineteen assessable patients were analyzed. The incidence of stage III (moderate) or stage IV (severe) renal dysfunction was 72%, 64%, and 75% for treatment with cyclophosphamide/methotrexate/fluorouracil, AC, and capecitabine, respectively. There was no relationship for any regimen between pretreatment renal function and the five end points. For AC, as CrCl increased, the odds of nonhematologic toxicity decreased (P = .008), whereas for capecitabine, as CrCl increased, the odds of experiencing toxicity of any type also increased (P = .035). Patients with renal insufficiency who received dose modifications were not at increased risk for complications compared with those who did not have renal insufficiency and received a full dose. Conclusion Excluding from clinical trials patients with renal insufficiency but good performance status on the basis of concern of excessive hematologic toxicity or poor outcomes may not be justified with appropriate dosing modifications. Results should be considered in the design of clinical trials for older patients.