OBJECTIVES:To explore the effects of ischaemia time (IT) in a multicentre cohort of patients with solitary kidney (SK), treated with partial nephrectomy (PN) for a renal mass, on short- and long-term kidney function, haemorrhagic risk and pathological outcomes. METHODS:This is an observational study of 426 patients with SK treated with on- and off-clamp PN for a single cT1-3 N0M0 renal mass from 2000 to 2023 at 19 global institutions. The primary outcomes were postoperative and 1-year renal function. The secondary outcomes of the study were haemorrhagic risk, defined as estimated blood loss (EBL) and peri-operative transfusions, and presence of positive surgical margins. The effect of IT and arterial clamping strategy was estimated using linear and logistic regressions for continuous and categorical outcomes, respectively. RESULTS:On-clamp PN was performed in 56% of patients (n = 237). The median (interquartile range [IQR]) age, body mass index, preoperative estimated glomerular filtration rate (eGFR), clinical size and PADUA score were 65 (58-71) years, 27 (24-29) kg/m2, 58 (45-46) mL/min, 3 (2-4.2) cm and 8 (7-10), respectively. The median (IQR) duration of IT was 19 (13-25) min. In multivariable linear and logistic regression analyses (MVA), IT was not associated with decreased postoperative eGFR (estimate -0.08 mL/min; P = 0.3) or 1-year eGFR (estimate -0.1 mL/min; P = 0.2). No association between on-clamp strategy and eGFR decline was recorded either postoperatively (estimate -3.11 mL/min; P = 0.1) or at 1 year (estimate -3.12 mL/min; P = 0.1). The median (IQR) EBL was lower in the on-clamp group at 200 (100-400) mL vs 300 (145-500) mL in the off-clamp group. In MVA predicting haemorrhagic risk, arterial clamping was associated with lower risk of transfusions (odds ratio 0.45; P = 0.01). CONCLUSIONS:In patients with SK, on-clamp PN did not affect long-term renal function and was associated with a modestly lower need for peri-operative transfusion. The routine use of the off-clamp technique is therefore not supported by these findings, although its selective application may remain appropriate in cases with a high risk of renal function decline.

Abstract Introduction This study aims to externally validate the preoperative risk evaluation for partial nephrectomy (PREP) score, recently introduced to predict the risk of major complications after partial nephrectomy based on patient characteristics, in a large multi‐institutional cohort of robot‐assisted partial nephrectomy (RAPN) patients. Materials and Methods A retrospective review was performed on the IRB‐approved, multi‐institutional United States Kidney Cancer Data Network (US‐KIDNET) to identify 10 154 patients who underwent RAPN from 2018 to 2025. Major complications were defined as Clavien–Dindo grade III–V within 30 days. Patients were assigned to risk categories for major complications based on weighted comorbidities, as defined by the PREP score, and the alignment of predicted complication rates with actual complication rates was evaluated. Discrimination was evaluated using the area under the receiver operating characteristic curve (AUC). Calibration was examined using the Hosmer–Lemeshow (HL) goodness‐of‐fit test. Subgroup analysis was performed by robotic platform and surgical approach. Exploratory univariate and multivariate logistic regression were performed to evaluate associations between individual PREP components and major complication rates. All computations were performed in Python (v3.8). Results A total of 8615 patients who underwent RAPN were included in the final validation cohort. The PREP score did not perform well in this robotic surgery cohort, with limited overall discrimination (AUC 0.547; 95% CI 0.518–0.580). On calibration, the model's predicted probabilities were not well‐aligned with observed outcomes (HL χ 2 = 150.2; p < 0.001). Performance did not differ significantly across robotic platform or surgical approach subgroups. In the adjusted analysis, coronary artery disease (CAD, aOR 2.22), chronic obstructive pulmonary disease (COPD, aOR 2.75), chronic kidney disease (CKD, aOR 1.48), and obesity (aOR 1.73) were independently associated with major complications, but not congestive heart failure (CHF; aOR 0.50, p = 0.36). Conclusion Our real‐world external validation for the PREP score demonstrates that this score does not perform well in a large, multicentre, robotic cohort. Our findings suggest that coefficient re‐estimation, rather than simple recalibration, may be required.

Introduction Administration of adjuvant immunotherapy for high-risk (T3) Renal Cell Carcinoma (RCC) has recently become a standard of care with publication of KEYNOTE-564 demonstrating survival benefit in this patient group. Presence of high tumor grade is increasingly understood as marker for adverse oncological outcomes in T1 and T2 RCC. We sought to compare survival outcomes of T1-T2 high-grade disease and T3 RCC. Methods Prospectively collected data from a multicenter database involving University of California San Diego Health (USA), IRCCS San Raffaele Hospital (Italy), Emory University Hospital (USA) and Tokyo Medical and Dental University (Japan) were retrospectively analyzed, collecting a total of 5452 non metastatic patients treated with radical or partial nephrectomy. Baseline patient [age, sex, Body Mass Index (BMI), Charlson Comorbidity Index (CCI)] and tumoral characteristics (histology, RENAL score, tumor size, pathological N stage] were evaluated. Kaplan-Meier survival analysis was used to compare cancer-specific survival (CSS) and overall survival (OS) in T1-T2 high-grade and T3 RCC. Cox regression was utilized to evaluate for predictors for CSM and ACM while controlling for demographic and pathological factors. Results Median follow-up was 61 months. A total of 5007 patients with a T1-T2 High Grade (HG) tumor and 445 patients with a T3 any Grade tumor were analyzed. Kaplan-Meier analysis revealed that the 5-year CSS for T1-T2 high-grade tumors was 87%, while for T3 tumors it was 86%, indicating comparable survival rates between the two groups (p=0.08). 5-year OS was similar, being 78% for T1-T2 HG and 78% for T3 any Grade (p=0.11). Cox regression analyses showed that stage (T1-T2-HG vs T3a stage) was not predictive of differences in CSM (HR 1.24, p=0.15), or in ACM (HR 1.25, p=0.06). Conclusions Cancer-specific mortality is comparable between T1-T2 high-grade tumors and T3 tumors while overall mortality is similar between T1-T2 HG and T3a any grade tumors. Hence, caution must be exercised when managing localized RCC with adverse pathological features, as its prognosis may be as severe as that of a locally advanced disease. Our findings suggest the need to reevaluate the inclusion criteria for adjuvant clinical therapy trials to consider T1-T2 high-grade renal cell carcinoma in future studies.

To compare the outcomes of Neoadjuvant Chemotherapy (NAC) versus Adjuvant chemotherapy (AC) in upper tract urothelial carcinoma (UTUC) with Clinical Nodal Disease (CN+). Multicenter retrospective analysis of patients with CN + who underwent RNU from the ROBUUST (ROBotic surgery for Upper Tract Urothelial cancer STudy) database. Patients were divided into those who received NAC versus AC. Primary outcome was all-cause mortality (ACM). Secondary outcomes were cancer-specific mortality (CSM) and recurrence. Cox-regression multivariable analysis (MVA) was used to elucidate predictive factors for ACM, CSM, and recurrence. Kaplan-Meier Analysis (KMA) was performed to analyze 5-year overall survival (OS), cancer-specific survival (CSS), and recurrence free survival (RFS). 102 patients were analyzed (53 neoadjuvant/49 adjuvant; median follow-up 17.0 months). Groups did not differ with respect to median age at diagnosis (p = 0.692), BMI (p = 0.551), clinical tumor size (p = 0.514), or ECOG performance status (p = 0.44). MVA revealed receipt of NAC to be associated with improved ACM (HR 0.36, p = 0.023), CSM (HR 0.38, p = 0.046), and recurrence (HR 0.51, p = 0.048). KMA comparing NAC and AC revealed significantly greater 5-year OS (65