The natural history of renal function after surgical management of renal cell carcinoma: Results from the Canadian Kidney Cancer Information System

Introduction and objective Patients who undergo surgical management of renal cell carcinoma (RCC) are at risk for chronic kidney disease and its sequelae. This study describes the natural history of renal function after radical and partial nephrectomy and explores factors associated with postoperative decline in renal function. Methods This is a multi-institutional cohort study of patients in the Canadian Kidney Cancer Information System who underwent partial or radical nephrectomy for RCC. Estimated glomerular filtration rate (eGFR) and stage of chronic kidney disease were determined preoperatively and at 3, 12, and 24 months postoperatively. Linear regression was used to determine the association between postoperative eGFR and type of surgery (radical vs. partial), duration of ischemia, ischemia type (warm vs. cold), and tumor size. Results and limitations With a median follow-up of 26 months, 1,379 patients were identified from the Canadian Kidney Cancer Information System database including 665 and 714 who underwent partial and radical nephrectomy, respectively. Patients undergoing radical nephrectomy had a lower eGFR (mean = 19 ml/min/1.73 m² lower) at 3, 12, and 24 months postoperatively (P<0.001). Decline in renal function occurred early and remained stable throughout follow-up. A lower preoperative eGFR and increasing age were also associated with a lower postoperative eGFR (P<0.01). Ischemia type and duration were not predictive of postoperative decline in eGFR (P>0.05). Severe renal failure (eGFR<30 ml/min/1.73 m²) developed postoperatively in 12.5% and 4.1% of radical and partial nephrectomy patients, respectively (P<0.001). Conclusions After the initial postoperative decline, renal function remains stable in patients undergoing surgery for RCC. Patients undergoing radical nephrectomy have a greater long-term reduction in renal function compared with those undergoing partial nephrectomy. Ischemia duration and type are not predictive of postoperative renal function when adhering to generally short ischemia durations.