Nephrometry Scores Show Limited Discrimination for Adverse Outcomes After RAPN in Larger Renal Tumors

Tumor complexity scoring supports preoperative planning for robot-assisted partial nephrectomy (RAPN), but evidence in larger tumors is limited. We evaluated whether PADUA and RENAL nephrometry scores are associated with early perioperative outcomes in a stage-focused cohort of pathological pT1b or higher renal tumors treated with multiport RAPN. We retrospectively reviewed a prospectively maintained single-center database of multiport RAPN cases (2011–2025). Patients with pathological pT1b–pT2a disease were included. The primary endpoint was a 30-day composite adverse outcome: major complications (Clavien–Dindo ≥3) and/or perioperative transfusion. Secondary endpoints were any complication (Clavien 1–5), transfusion, warm ischemia time (WIT; continuous and >25 min), operative time, length of stay, and trifecta achievement. Associations were tested using logistic regression (penalized models for sparse outcomes), linear regression, and AUC; β represents the adjusted change in the outcome per 1-point increase in score. In total, 109 patients were included (PADUA available in 108; RENAL in 83). Neither PADUA nor RENAL was independently associated with the composite adverse outcome, and discrimination was limited (PADUA AUC 0.583, 95% CI 0.411–0.733; RENAL AUC 0.563, 95% CI 0.347–0.775; p = 0.738). Both scores were associated with intraoperative metrics. Each 1-point increase in PADUA correlated with longer WIT (β 1.13 min; 95% CI 0.20–2.07; p = 0.019) and operative time (β 4.55 min; 95% CI 0.20–8.90; p = 0.043). Each 1-point increase in RENAL correlated with longer WIT (β 1.33 min; 95% CI 0.25–2.40; p = 0.018) and operative time (β 5.01 min; 95% CI 1.62–8.40; p = 0.005). Trifecta achievement was not significantly associated with either score. In patients with pathological pT1b or higher renal tumors treated with multiport RAPN, PADUA and RENAL scores were not associated with a 30-day composite adverse outcome and had limited discrimination for major morbidity and/or transfusion, but both correlated with WIT and operative time. Larger externally validated cohorts incorporating longitudinal renal function and broader patient-level risk factors are needed to refine preoperative risk assessment in larger renal tumors.