Applicability of the Japanese equation for estimating glomerular filtration rate in patients with advanced-stage thoracic cancer

Abstract Background The 24-hour creatinine clearance (24-h Ccr) and the Cockcroft-Gault equation (CG) are commonly used as markers of renal function in clinical practice. However, the utility of the Japanese equation for estimating glomerular filtration rate (eGFR) in cancer patients has not yet been evaluated. The aim of this cross-sectional study was to investigate the extent and correlating factors for differences between eGFR and both 24-h Ccr and CG in advanced-stage thoracic cancer patients. Methods eGFR, 24-h Ccr, and CG were calculated in 90 patients with thoracic malignancies. We evaluated how these three parameters are affected by clinical factors, including age, body surface area, serum creatinine concentration, and body mass index. Results eGFR and CG were significantly correlated with 24-h Ccr ( r = 0.64, p < 0.001 and; r = 0.67, p