Analysis of Renal Functional Outcomes After Radical or Partial Nephrectomy for Renal Masses ≥7 cm Using the RENAL Score

OBJECTIVE To determine if partial nephrectomy (PN) confers a renal functional benefit compared to radical nephrectomy (RN) for clinical T2 renal masses (T2RM) when adjusting for tumor complexity characterized by the RENAL nephrometry score. METHODS A 2-center study of 202 patients with T2RM undergoing RN (122) or PN (80) (median follow-up, 41.5 months). RN and PN cohorts were subanalyzed according to RENAL sum as a categorical variable of < 10 or >= 10. Primary outcome was median change in estimated glomerular filtration rate (Delta eGFR) between preoperative to 6 months postoperative. Logistic regression-identified prognostic factors and survival models analyzed association between the RENAL sum and the freedom from de novo chronic kidney disease (CKD; eGFR< 60 mL/min/1.73m(2)). RESULTS No significant differences existed between PN and RN for RENAL score. Delta eGFR was greater in RN (-19.7) vs PN (-11.9; P = .006). De novo CKD was 40.2% after RN vs 16.3% after PN (P < .001). RENAL score >= 10 (odds ratio, 6.67; P = .025) and RN among patients with RENAL score < 10 (odds ratio, 24.8; P < .001) were independently associated with de novo CKD at 6 months by logistic regression. Among patients with RENAL score < 10, median CKD-free survival was PN 38 vs RN 16 months (P = .001). Cox proportional hazard demonstrated decreasing risk of CKD for PN vs RN from RENAL 10 (hazard ratio, 0.836) to RENAL 6 (hazard ratio, 0.003; P = .001). CONCLUSION RN is independently associated with decreased renal function compared to PN for T2RM with RENAL sum <= 10, but not > 10, with larger relative decrease in eGFR for each decrease in RENAL sum. Further investigation is required to determine optimal candidates for PN in T2RM. (C) 2015 Elsevier Inc.