Cirrincione, Constance T

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.

PurposeOptimal adjuvant chemotherapy for early-stage breast cancer balances efficacy and toxicity. We sought to determine whether single-agent paclitaxel (T) was inferior to doxorubicin and cyclophosphamide (AC), when each was administered for four or six cycles of therapy, and whether it offered less toxicity.Patients and MethodsPatients with operable breast cancer with 0 to 3 positive nodes were enrolled onto the study to address the noninferiority of single-agent T to AC, defined as the one-sided 95% upper-bound CI (UCB) of hazard ratio (HR) of T versus AC less than 1.30 for the primary end point of relapse-free survival (RFS). As a 2 × 2 factorial design, duration of therapy was also addressed and was previously reported.ResultsWith 3,871 patients enrolled onto the trial, a median follow-up period of 6.1 years, and 437 RFS events, we achieved an HR of 1.26 (one sided 95% UCB, 1.48; favoring AC does not allow a conclusion of noninferiority of T with AC; UCB > 1.3). With 266 patient deaths, the HR for overall survival (OS) was 1.27 favoring AC (UCB, 1.56). The estimated absolute advantage of AC at 5 years is 3% for RFS (91 v 88%) and 1% for OS (95 v 94%). All nine treatment-related deaths were patients receiving AC and are included in the analyses of both RFS and OS. Hematologic toxicity was more common in patients treated with AC, and neuropathy was more common in patients treated with T.ConclusionThis trial did not show noninferiority of T to AC, a conclusion that is unlikely to change with additional events and follow-up. T was less toxic than AC.