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

Abstract

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 7days of RN, at 3months, 1 and 3years. We divided patients into three groups based on tumour size: A: ⩽4cm, B: 4-7cm, C: >7cm. 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<60mL/min/1.73m(2)).

Results: The preoperative GFR was significantly different among the three groups (A: 83.0, B: 82.0, C: 79.4ml/min/1.73m(2), P=0.040). The decrease in GFR from preoperative to within 7days was greater in group A than in groups B and C (28.2 versus 24.2 versus 18.5ml/min/1.73m(2), P<0.001). The GFR at 1year postoperative was lower in group A than in group C (58.4 versus 61.5ml/min/1.73m(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 1year (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 7cm or less.

Keywords: Chronic kidney disease; Nephrectomy; Renal cell carcinoma; Renal function; Tumour size.