Outcomes of endoscopic management for upper tract urothelial carcinoma: A multi-center international cohort analysis

Introduction Upper tract urothelial carcinoma (UTUC) is a rare and aggressive malignancy with significant morbidity, often requiring radical nephroureterectomy (RNU) as the standard of care. Endoscopic ablation has emerged as a kidney-sparing alternative, particularly for low-risk UTUC. Given the rarity of UTUC, generating high-quality evidence for treatment strategies remains challenging. This study presents a large, multi-institutional analysis of outcomes following primary endoscopic ablation for UTUC. Methods A retrospective analysis of 432 patients across 11 institutions who underwent first-time endoscopic treatment for UTUC with curative intent between December 2003 and January 2023 was performed. Baseline demographics, tumor characteristics, and procedural details were collected. Recurrence was categorized as ipsilateral, distant, or bladder recurrence, with overall survival (OS) as the primary outcome. Univariate and multivariate Cox regression models were used to identify predictors of recurrence and survival. Results At a median follow-up of 21 months, ipsilateral recurrence occurred in 232 patients (54%), while 55 (13%) developed distant metastases. The OS rate was 86%, with 29 patients (6.7%) dying within the first 12 months. On univariate analysis, the presence of a tumor not involving the renal pelvis (HR 0.71, P = 0.04) and use of a ureteral access sheath (UAS) (HR 0.65, P = 0.03) were associated with lower ipsilateral recurrence rates. On multivariate analysis, only UAS use remained significant (HR 0.39, P < 0.01). High-grade tumors were significantly associated with poorer OS (HR 3.59, P < 0.01). Conclusions Endoscopic ablation is a feasible kidney-sparing alternative for UTUC. Ipsilateral recurrence rate is approximately 50% with over 10% of patients developing metastatic disease. UAS use may reduce UTUC recurrence risk.