Impact of positive ureteral margin on upper tract recurrence after radical cystectomy for bladder cancer.

872 Background: A positive ureteral margin has been considered a key risk factor for upper tract recurrence (UTR) following radical cystectomy (RC) for bladder cancer, supporting intraoperative frozen section analysis to ensure negative margins. This study evaluated the impact of positive ureteral margins on UTR among patients with bladder cancer who underwent RC. Methods: Using our IRB-approved RC database, we identified all patients who underwent RC between 1984 and 2024. Patients with pathology-confirmed UTRs were identified. Cox regression was used to identify the predictive factors for UTR. Results: A total of 3544 patients, mostly male (n=2827, 79.8%) with a median age of 69 (IQR: 61-75) years, were included (Table 1). A total of 258 (7.3%) patients had positive surgical margins on permanent pathology, including 69 (2.0%) with positive ureteral margins. UTRs were identified in 55 (1.5%) patients at a median time of 37.4 (IQR: 14.0 – 65.7) months. Only 2 of the 69 (2.9%) patients with a positive ureteral margin at the time of RC developed UTR – one at 4.2 and the other at 43.8 months. Cox regressions confirmed that neither positive ureteral margin (HR: 2.6, 95%CI: 0.6 – 10.8, p = 0.180), nor overall surgical margin (HR: 1.9, 95%CI: 0.7 – 5.4, p = 0.205) were associated with higher risk of UTR. Hydronephrosis was the only significant predictor of UTR in univariate analysis and remained significant after adjusting for positive ureteral margin in a multivariate analysis (HR: 3.1, 95%CI: 1.8 – 5.4, p < 0.001). Conclusions: UTR occurred in only 1.5% of patients following RC, corresponding to less than 5% of patients with positive ureteral margins. These findings suggest that the necessity of routine frozen section during RC may warrant reconsideration. Larger multi-institutional studies are warranted to validate these results. Baseline characteristics. Charleson Comorbidity Index 0 1024 (29.3%) 1 1017 (29.0%) > 2 1461 (41.7%) Presence of hydronephrosis 837 (23.6%) History of Neoadjuvant Chemotherapy 696 (19.6%) Pathologic Stage < pT2N0 2087 (58.9%) > pT2N0 635 (17.9%) pN+ 822 (23.2%) Histology (Pure Urothelial) 2667 (75.2%) History of Adjuvant Chemotherapy 539 (15.2%)