Comparative Study of Carboplatin Dosing in Lung Cancer Patients Using the Calvert Formula and Four Equations for Estimating Glomerular Filtration Rate

Several studies have been conducted to estimate more accurate and precise glomerular filtration rate (GFR) in cancer patients; however, studies on determining carboplatin doses by the renal functions of Korean cancer patients have been rarely implemented. The aim of this study was to compare carboplatin doses calculated by the Calvert formula based on estimated GFRs with various equations with its dose prescribed by the physicians. This study was retrospectively conducted in patients (≥18 years) with lung cancer who had received carboplatin between September 2011 and August 2013. Data were collected by reviewing the electronic medical records (EMRs). Among 129 patients with lung cancer, 95 were males. Mean age was 65.0 years, and mean estimated GFRs of Cockcroft-Gault, Jelliffe, Modification of Diet in Renal Disease (MDRD), and MDRD for Japanese (J-MDRD) formulae were 65.7, 63.2, 74.1, and 57.5 mL/min, respectively. Compared with mean prescribed carboplatin dose (444.4 mg), its mean estimated doses by Cockcroft-Gault, Jelliffe, MDRD, and J-MDRD formulae were 465.8, 452.5, 508.6, and 423.3 mg, respectively. The carboplatin doses estimated by Cockcroft-Gault and Jelliffe formulae showed relatively smaller bias and better precision than those estimated by MDRD and J-MDRD formulae. The carboplatin dose calculated based on estimated GFR with MDRD formula showed the biggest bias and lowest precision. When the characteristics of patients in this study were considered, the J-MDRD formula may estimate more accurate GFRs than other formulae originated from Western patients. Further related studies are needed for Korean cancer patients.