Cumulative incidence and risk factors for recurrence of upper tract urothelial carcinoma in patients undergoing radical cystectomy.

Objectives: This study aimed to evaluate the cumulative incidence of upper tract urothelial carcinoma (UTUC) recurrence and identify its risk factors in patients who underwent radical cystectomy (RC). Patients and methods: We performed RC on 385 patients between September 2002 and February 2020. After excluding 20 patients-13 with simultaneous nephroureterectomy, 6 with distal ureteral stump positivity and 1 with urachal cancer-365 patients were included in the analysis. To predict UTUC recurrence, we examined the cancer extension pattern in cystectomy specimens and categorized them into three types: cancer located only in the bladder (bladder-only type), cancer extending to the urethra or distal ureter (one-extension type) and cancer extending to both the urethra and distal ureter (both-extension type). We determined hazard ratios for UTUC recurrence for each covariate, including this cancer extension pattern. Results: Of the 365 patients, 60% had the bladder-only type, 30% had the one-extension type and 10% had the both-extension type. During a median follow-up period of 72 months for survivors, UTUC recurred in 25 of the 365 patients, with cumulative incidences of 3.7% at 5 years and 8.3% at 10 years. The median interval from cystectomy to recurrence was 65 months (interquartile range: 36-92 months). In the multivariate analysis, the extension pattern was a significant predictor of UTUC recurrence. The hazard ratios for UTUC recurrence were 3.12 (95% confidence interval [CI] = 1.15-8.43, Conclusions: The cancer extension pattern in cystectomy specimens is predictive of UTUC recurrence. A more extensive cancer extension in cystectomy specimens elevates the risk of subsequent UTUC recurrence. Intensive long-term monitoring is essential, particularly for patients with the both-extension type.