PD41-05 PROPENSITY SCORE MATCHED COMPARISON OF MINIMALLY INVASIVE PARTIAL AND RADICAL NEPHRECTOMY FOR CLINICAL T2A RENAL MASS: ANALYSIS OF THE ROBOTIC SURGERY FOR LARGE RENAL MASSES (ROSULA) GROUP

INTRODUCTION AND OBJECTIVES: While emerging data suggest feasibility and safety of minimally invasive partial nephrectomy (MIS-PN) for T2a renal mass (T2aRM), comparative analyses to minimally invasive radical nephrectomy (MIS-RN) are limited. We conducted a propensity score-matched comparison of outcomes of MIS-RN and PN in clinical T2a renal mass utilizing a large multicenter registry. METHODS: Retrospective multicenter analysis of MIS-PN and RN for cT2aRM (T2aN0M0) [RObotic SUrgery for LArge renal mass (ROSULA) Group]. Cohorts were propensity matched for age, sex, BMI and clinical tumor size using a 2:1 ratio for RN:PN. Primary outcome was disease-free survival (DFS), with secondary outcomes of overall survival (OS), change in estimated glomerular filtration rate (&Dgr;eGFR), de novo eGFR<60 mL/min/1.73m2 and eGFR<45. Cox Regression (MVA) and Kaplan-Meier analyses (KMA) were carried out for outcomes. RESULTS: 648 patients (216 PN/432 RN, median follow up 18 months) were matched. There was no significant difference in age (p=0.302), sex (p=0.505), BMI (p=0.221), or tumor size (RN 8.16 vs. PN 8.06 cm, p=0.10). No differences were noted in Clavien 3/4 complications (p=0.062) and readmissions (p=0.139). PN had lower &Dgr;eGFR (9.4 vs. 24.4, p<0.001), de novo eGFR <60 (p<0.001) and de novo eGFR<45 (4.0% vs. 18.8%, p<0.001). MVA revealed increasing ASA score (HR 2.7, p=0.044) and sarcomatoid histology (HR 5.3, p=0.001), but not surgery type (p=0.601) to be associated with worsened all-cause mortality. Pathologic upstaging (HR 2.5, p=0.010), high tumor grade (HR 2.7, p=0.016), and sarcomatoid histology (HR 2.4, p=0.033) were associated with recurrence, while surgery type (p=0.550) was not. Increasing age (HR 1.1, p<0.001) and RN (HR 4.6, p =0.001) were predictors for de novo eGFR<45. KMA showed 77.8% and 79.4% 5-year DFS for patients undergoing MIS-PN and RN, respectively (Figure 1; p=0.410), and 77.1% and 88.2% 5-year OS for patients who underwent MIS-PN and RN, respectively (p=0.280). CONCLUSIONS: In a propensity matched cT2a cohort, MIS-PN demonstrated similar oncologic outcomes while conferring functional benefit. When feasible, MIS-PN may be considered as a viable option for select cT2a renal masses. Figure. No caption available. Source of Funding: None