Risk of Recurrence and Progression After Endoscopic Kidney-sparing Surgery for Upper Tract Urothelial Carcinoma

Background and objective: Our aim was to identify key prognostic factors for recurrence and progression of upper tract urothelial carcinoma (UTUC) after endoscopic kidney-sparing surgery (eKSS), and to provide a reliable, easy-to-use, risk stratification model. Methods: We used data from a retrospective multicenter database for 358 patients with UTUC who underwent eKSS with curative intent between 2010 and 2021. A scoring system to predict recurrence-free survival (RFS) and progression-free survival (PFS) was developed using regression analyses. The discriminative ability of the score was estimated using the C index. Key findings and limitations: The analysis included 223 patients, of whom 106 (48%) had recurrence and 37 (17%) had progression at median follow-up of 39 mo. Scoring systems were created that included synchronous bladder cancer (BCA; hazard ratio [HR] 1.52), high grade at biopsy (HR 1.38), multifocal UTUC (HR 1.12), and history of UTUC (HR 1.43) as factors for RFS, and synchronous BCA (HR 1.44), high grade at biopsy (HR 1.38), size ≥2 cm (HR 1.23), and positive cytology (HR 1.64) as factors for PFS. The C index was 0.60 for 5-yr RFS and 0.64 for 5-yr PFS. Three risk groups for each model were identified. The 5-yr cumulative incidence rates for the low-risk, intermediate-risk, and high-risk groups were 37%, 58%, and 70% for recurrence, and 4%, 18%, and 30% for progression, respectively. Limitations include the lack of external validation, a heterogeneous eKSS cohort, and limited follow-up. Conclusions and clinical implications: We propose a novel risk stratification model for patients with UTUC treated with eKSS that includes key predictors for recurrence and progression and an intermediate-risk UTUC category with distinct outcomes.