Comparison of three equations for estimating glomerular filtration rate as predictors of cisplatin-related acute kidney injury in lung cancer patients with normal renal function.

Objective: Cisplatin-associated acute kidney injury is a common clinical event that causes increased morbidity and mortality in cancer patients even if they are categorized as having normal functioning kidneys. We aimed to determine predictive factors that can predict acute kidney injury associated with cisplatin therapy in patients with normal renal function by comparison of pre-chemotherapy estimated glomerular filtration rates calculated separately by Cockcroft and Gault (CG), the Modification of Diet in Renal Disease (MDRD), and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPİ) equations and accompanying patient-associated factors.

Materials and methods: A total of 200 patients diagnosed with lung cancer and determined to have normal functioning kidneys and considered cisplatin eligible by the attending physician before chemotherapy were included in this retrospective study. Acute kidney injury after cisplatin chemotherapy (c-AKI) was determined according to the National Cancer Institute's Common Terminology Criteria for Adverse Events v4.03. Pre-chemotherapy serum laboratory parameters and clinico-histopathological characteristics of patients were recorded from the hospital electronic system. The optimal cut-off for eGFR methods was determined by the area under the receiver operating characteristic curve (ROC-AUC) analysis. Predictive factor analysis for c-AKI was performed by regression analyses.

Results: C-AKI developed in 39 (19.5%) patients. In the univariate analysis, a significant correlation was observed between c-AKI and high body mass index (BMI) before treatment, older age (>62.5), female gender, eGFR by MDRD (≤94.5 mL/min) and eGFR by CKD-EPI (≤91.5 mL/min). There was no relation between eGFR by CG and c-AKI. Two different multivariate models were established. Model 1 showed that female gender (odds ratio [OR] =4.90, 95% confidence interval [CI]: 1.52-15.79, P = 0.008) and eGFR by MDRD less than or equal to 94.5 mL/min (OR = 3.52, 95% CI: 1.68-7.38, P = 0.001) were predictive markers for c-AKI. In Multivariate Model 2, female gender (OR = 5.51, 95% CI: 1.70-17.83, P = 0.004) and eGFR by CKD-EPI less than or equal to 91.5 mL/min (OR = 3.52, 95% CI: 1.67-7.42, P = 0.001) were found to be predictive markers for c-AKI.

Conclusions: This study revealed that eGFR calculated based on MDRD (≤94.5 mL/min/m2) or CKD-EPI (≤91.5 mL/min/m2) before chemotherapy indicates a strong tendency for c-AKI. In addition, we detected a high risk of c-AKI for females compared to their counterparts. Although eGFR 60 mL/min is considered the threshold level to accept patients as cisplatin-eligible, we recommend close follow-up of high-risk patients for cisplatin nephrotoxicity we detected in our models.