Nephron Sparing Surgery Associated With Better Survival Than Radical Nephrectomy in Patients Treated for Unforeseen Benign Renal Tumors

Introduction: To evaluate the role of the surgical technique used for the treatment of benign renal tumors, with regard to renal function and overall survival (OS) in patients without cancer-related mortality. Technical considerations: The study included 506 patients, mean age of 63.3 years, with histologically proven benign renal lesions originating from 5 European centers. Retrospective data from each hospital were retrieved and merged into a common database for analyses. OS, American Society of Anesthesiology score, and renal functions were measured in relation to surgical technique. The Mann-Witney U-test, the paired t-test, and Cox's multivariate analysis were used.Patients treated with radical nephrectomy had significantly reduced renal function postoperatively compared with nephron sparing surgery (NSS). OS was significantly reduced after radical nephrectomy compared with NSS (P = .012), a survival difference that remained significant [hazard ratio (HR) 0.042, 95% confidence interval (CI) 0.221-0.972, P = .042] in multivariate analysis, together with age at diagnosis (HR 1.065, 95% CI 1.026-1.106, P = .001) and American Society of Anesthesiology score (HR 2.361, 95% CI 1.261-4.419, P = .007). Also renal function assessed by estimated glomerular filtration rate significantly correlated to survival in univariate analysis, but did not remain independent after multivariate analysis. Oncocytoma was the most frequent benign lesion, followed by angiomyolipoma. Conclusion: The present study in patients with benign renal tumors shows that the remaining renal function and OS correspond to the choice of surgical procedure. Our results support the recommendation to perform NSS whenever possible when surgery is performed for patients with renal masses. The limitations of the study are the retrospective design and the selection bias for the surgical approach.