SUO 2017: Safe And Effective Partial Nephrectomy Is Feasible In Appropriately Selected Patients With Complex (Renal Nephrometry Score 10-12) Renal Tumors: A Multi-institutional Analysis

Washington, DC ( Introduction: Current guidelines recommend partial nephrectomy (PN) for clinical T1a renal masses; however, the decision to perform PN or radical nephrectomy (RN) for localized, anatomically complex renal masses remains debated. This led the authors to examine differences in oncologic and perioperative outcomes between PN and RN for highly complex tumors.

Methods: Prospective renal surgery databases from four institutions were combined. Patients were included if they had PN/RN for RENAL nephrometry score (NS) 10-12 tumors. Exclusion criteria were pathologic evidence of N+ or M+ disease and benign histology. The primary outcome was overall survival (OS). Secondary outcomes were recurrence-free survival (RFS), positive
margins (PM), and 30-day complications. Multivariable logistic regression analysis was used to test for associations with receipt of RN, PN, and 30-day complications. OS and RFS were analyzed using Kaplan-Meier and Cox proportional hazards models (CPHM).

Results: 741 patients (271 PN, 470 RN) had a median follow-up of 30.6 (IQR 7.8-59.3) months. RN was more often performed in females (OR 1.57, 95% CI 1.02-2.41, p=0.04), age>70 (OR 2.81, 1.44-5.48, p<0.01), or higher NS tumors (OR for NS 12: 7.29, 1.67-31.9, p=0.01). 5-year OS was 94.7% for PN and 67.3% for RN (p<0.01). This OS difference was not apparent after adjustment (HR 5.18, 0.70-38.05, p=0.11). Factors associated with reduced OS on CPHM were age>70 years (HR 2.62, 1.82- 3.78), NS 12 (HR 1.96, 1.67-2.30), Fuhrman grade 3-4 (HR 2.03, 1.91-2.15) and ≥pT3 stage (HR 2.01, 1.54-2.62, p<0.01 for all). 5-year RFS was 92% for PN and 76.9% for RN (p < 0.01) and persisted on CPHM (HR 3.58, 2.84-4.53,p<0.01). Risk of PM was not different between PN and RN (OR 0.55, 0.22-1.39); however, each 100ml increase in estimated blood loss was associated with a 3.8% increase in PM (OR 1.038, 1.01-1.06, p < 0.01). No differences in 30-day complications between PN and RN (OR 1.48, 95% CI 0.90-2.42) were observed.

Conclusion: PN for complex NS was not associated with increased oncologic risk or 30-day complications. The finding of worse RFS for RN likely reflects unmeasured selection bias. The authors concluded that complex NS should not blindly prevent performance of PN at experienced centers.

Presented by: Benjamin Ristau, Division of Urology, UConn Health, Farmington, CT

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 18th Annual Meeting of the Society of Urologic Oncology, November 29-December 1, 2017 – Washington, DC