Comparison of Clinical Outcomes of Upper Tract Urothelial Carcinoma between Patients after Renal Transplantation and on Dialysis: A Long-Term Single-Center Cohort Study.

BACKGROUND: This study aimed to compare clinical outcomes between patients who received renal transplantation (RT) and those maintained on dialysis. PATIENTS AND METHODS: We retrospectively analyzed 133 patients (34 RT, 99 dialysis) with unilateral UTUC treated with unilateral radical nephroureterectomy (RNU). Propensity score matching (PSM) with a 0.02 caliper balanced baseline characteristics, yielding 34 matched pairs. Overall survival was assessed by Kaplan-Meier; cancer-specific survival, bladder recurrence-free survival, and contralateral recurrence-free survival were analyzed via cumulative incidence functions and Gray's test in a competing-risk framework. Multivariate Fine-Gray regression identified independent predictors. Sensitivity analyses used the unmatched cohort, and all models were validated by a biostatistician. RESULTS: Compared with dialysis patients, the RT group was significantly younger and had a higher proportion of larger tumors. Before PSM, Kaplan-Meier analysis revealed significant differences in contralateral recurrence-free survival (CRFS) and cancer-specific survival (CSS) between the two groups, but no significant differences in overall survival (OS) or bladder recurrence-free survival (BRFS). Multivariate Fine-Gray regression identified RT as an independent risk factor for worse CRFS, but not for CSS. After PSM, a significant difference in CRFS persisted between the groups, while no significant differences were observed in OS, CSS, or BRFS. CONCLUSIONS: RT yields overall survival comparable to dialysis but confers a substantially increased risk of contralateral recurrence. Prophylactic contralateral nephroureterectomy should be reserved for highly selected high-risk patients after multidisciplinary evaluation.