Clinical predictors of the estimated glomerular filtration rate 1 year after radical nephrectomy in Japanese patients

PURPOSE To evaluate renal function 1 year after radical nephrectomy (RN) for renal cell carcinoma, the preoperative predictors of postnephrectomy renal function were investigated by sex, and equations to predict the estimated glomerular filtration rate (eGFR) 1 year after RN were developed. MATERIALS AND METHODS A total of 525 patients who underwent RN between May 2007 and August 2011 at Tohoku University Hospital and its affiliated hospitals were prospectively evaluated. Overall, 422 patients were analyzed in this study. RESULTS Independent preoperative factors associated with postnephrectomy renal function were different in males and females. Preoperative eGFR, age, tumor size, and body mass index (BMI) were independent factors in males, while tumor size and BMI were not independent factors in females. The equations developed to predict eGFR 1 year after RN were: Predicted eGFR in males (mL/min/1.73 m2)=27.99-(0.196×age)+(0.497×eGFR)+(0.744×tumor size)-(0.339×BMI); and predicted eGFR in females=44.57-(0.275×age)+(0.298×eGFR). The equations were validated in the validation dataset (R2=0.63, p<0.0001 and R2=0.31, p<0.0001, respectively). CONCLUSIONS The developed equations by sex enable better prediction of eGFR 1 year after RN. The equations will be useful for preoperative patient counseling and selection of the type of surgical procedure in elective partial or RN cases.