Predicting positive surgical margins in patients treated with robot-assisted partial nephrectomy: Results from a prospectively maintained dataset of a single tertiary referral center

Aim: To identify the incidence and evaluate predictors of positive surgical margins (PSMs) after robot-assisted partial nephrectomy (RAPN) in patients with clinical T1 renal cell carcinoma (RCC). Methods: After securing ethics committee approval, we analyzed our institution’s prospectively maintained RCC database. Our cohort included 1611 patients who underwent RAPN between January 2017 and December 2022. Surgical specimens were evaluated using standard practices, and the International Society of Urological Pathology (ISUP) grading system was employed. Results: The majority (69.5%) of the 1,611 patients were males. Median age and Body Mass Index were 62.6 years and 26.9 kg/m2, respectively. Overall, 18.6% and 21.1% of the patients had an Eastern Cooperative Oncology Group (ECOG) score ≥ 1 and American Society of Anesthesiologists physical status (ASA PS) score ≥ 3, respectively. Surgical indications were elective in 90.5% of cases. The preoperative aspects and dimensions used for an anatomical (PADUA) score median was 8.0 (interquartile range: 7.0-9.5). The predominant histotype was clear cell RCC, accounting for 70.4% of the cohort. PSMs were detected in 6.7% of the patients. Multivariable logistic regression showed surgical indications with an odds ratio (OR) of 6.06 (P < 0.001), surface, intermediate, base (SIB) score > 1 with an OR of 2.37 (P = 0.001), and PADUA score with an OR of 1.10 (P = 0.006) were significant predictors of PSMs. Conclusion: Attaining negative margins remains the oncological cornerstone of partial nephrectomy. Our data underscore that tumor-specific (PADUA score) and surgical parameters (imperative indication, SIB score > 1, off-clamp approach) are the principal determinants for PSMs after RAPN.