Partial nephrectomy is associated with improved overall survival compared to radical nephrectomy in patients with unanticipated benign renal tumours

Background: Partial nephrectomy (PN) has been associated with improved overall survival (OS) in select cohorts with localised renal masses when compared to radical nephrectomy (RN). The driving forces behind these differences have been difficult to elucidate given the heterogeneity of previously compared cohorts. Objective: Compare OS in a subset of patients with unanticipated benign renal masses to minimise the confounding effect of cancer. Design, setting, and participants: We retrospectively evaluated 2608 consecutive clinical T1 enhancing renal masses that were treated with extirpative surgery at our institution between 1999 and 2006. Of these, 499 tumours (19%) were found to be benign on final pathology. Preoperative data and renal functional data were used to generate a propensity model that was then plugged into a multivariate model of survival. Median follow-up for the entire cohort was 50 mo (interquartile range [IQR]: 32-73). Intervention: All patients underwent PN or RN. Measurements: We measured OS and cardiac-specific survival. Results and limitations: Five-year OS estimates for the PN (n = 388) and RN (n = 111) cohorts were 95% (95% confidence interval [CI], 93-98) versus 83% (95% CI, 74-90), respectively (P < 0.0001). On multivariate analysis, controlling for both comorbidity and age, RN was associated with a 2.5-fold increased risk of death compared to PN (hazard ratio [HR]: 2.5; 95% CI, 1.3-5.1). Postoperative estimated glomerular filtration rate (eGFR) was also an independent predictor of OS and cardiac-specific survival (HR: 0.97; 95% CI, 0.95-0.99 and HR: 0.96; 95% CI, 0.93-0.99, respectively). The retrospective nature of this analysis limits the strength of the conclusions. Conclusions: PN was associated with better OS when compared to RN in patients with unanticipated benign tumours. This observed survival advantage appears partly to be the result of better preservation of eGFR, but other kidney functions or unmeasured factors may also play a role. These data indicate that PN should be aggressively pursued in any patient where PN is technically feasible.