Impact of the CKD-EPI Equation for Estimating Renal. Function on Eligibility for Cisplatin-based Chemotherapy in Patients With Urothelial Cancer

Combination cisplatin-based chemotherapy is indicated for patients with advanced bladder cancer, but use is often limited due to renal insufficiency. In this study, we retrospectively evaluated the renal function in patients with urothelial cancer by using 2 formulas and determined that the Chronic Kidney Disease Epidemiology Collaboration formula is less likely to deem a patient ineligible for cisplatin-based therapy compared with the Cockroft-Gault formula by using standard renal function thresholds. This finding warrants further prospective evaluation. Background: Although a creatinine clearance (CrCl) of <60 mL/min, as calculated by the Cockroft-Gault (CG) equation, is a commonly used threshold for cisplatin-ineligibility, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation has recently emerged as a more accurate method of estimating renal function. We sought to determine the impact of using the CKD-EPI equation for estimating renal function on cisplatin eligibility. Methods: All patients pathologically diagnosed with muscle invasive and/or metastatic bladder urothelial carcinoma N or M positive) at Mount Sinai Medical Center between January 1, 2000, and January 27, 2011, were identified. For each patient, CrCl was estimated by using the CG equation and glomerular filtration rate (GFR) was estimated by using the CKD-EPI equation. The patients were considered cisplatin-ineligible if CrCl <60 mL/min or if GFR was <60 mL/min per 1.73 m(2). Results: A total of 116 patients were included. The median CrCl estimated by CG was 58.93 mL/min, whereas the median GFR estimated by CKD-EPI was 64.67 mL/min per 1.73 m2. When using the CG formula, 53% of our cohort was cisplatin ineligible, whereas 46% of the cohort was ineligible when using the CKD-EPI formula. The probability of deeming a patient ineligible when using the CG formula was 17% higher than the probability of deeming a patient ineligible when using the CKD-EPI formula: PR 1.17 (95% CI, 1.03-1.34); P = .0203. Conclusion: In our retrospective study, the CKD-EPI formula was less likely to deem a patient ineligible for cisplatin-based therapy compared with the CG formula. This finding was hypothesis generating, and prospective evaluation is necessary to determine the clinical relevance of using this more accurate method of renal function assessment in chemotherapy decision making. (C) 2012 Elsevier Inc. All rights reserved.