Small tumour size is associated with new-onset chronic kidney disease after radical nephrectomy in patients with renal cell carcinoma

Background: To investigate the impact of tumour size on postoperative glomerular filtration rate (GFR) in patients undergoing radical nephrectomy (RN) for renal cell carcinoma (RCC). Methods: We retrospectively identified 1371 patients who underwent RN between 1995 and 2010. Serum creatinine levels were measured preoperatively, within 7 days of RN, at 3 months, 1 and 3 years. We divided patients into three groups based on tumour size: A: <= 4 cm, B: 4-7 cm, C: >7 cm. The changes in GFR were compared and multivariate logistic regression was used to analyse the predictive value of tumour size for new-onset chronic kidney disease (CKD, GFR < 60 mL/min/1.73 m(2)). Results: The preoperative GFR was significantly different among the three groups (A: 83.0, B: 82.0, C: 79.4 ml/min/1.73 m(2), P = 0.040). The decrease in GFR from preoperative to within 7 days was greater in group A than in groups B and C (28.2 versus 24.2 versus 18.5 ml/min/1.73 m(2), P < 0.001). The GFR at 1 year postoperative was lower in group A than in group C (58.4 versus 61.5 ml/min/1.73 m(2), P = 0.009), in contrast to preoperative GFR. The incidence of GFR decrease >30% was higher in Group A than in Groups B and C at 1 year (52.4% versus 41.5% versus 33.7%, P < 0.001). On multivariate analysis Groups A and B had a 2.37-fold (95% confidence interval (CI) 1.56-3.60, P < 0.001) and 2.24-fold (95% CI 1.49-3.38, P < 0.001) higher risk of new-onset CKD compared with Group C. Conclusions: Small tumour size is associated with CKD after RN. Partial nephrectomy should be considered in patients with tumour size 7 cm or less. (C) 2013 Elsevier Ltd. All rights reserved.