Incidence and Predictors of Secondary Upper Tract Urothelial Cancer in Patients with High-Risk Non-Muscle Invasive Urinary Bladder Cancer and its Impact on Imaging Surveillance: A Retrospective Analysis with 1501 Patients

Objectives: We aimed to study the incidence and predictors of upper tract urothelial cancer (UTUC) in patients with high-risk non-muscle invasive bladder cancer (HR-NMIBC). Methods: Patients who had HR-NMIBC were reviewed to identify those who subsequently developed UTUC. Complete transurethral resection was performed, and biopsies were collected for histopathology followed by intravesical chemoimmunotherapy. Patients were screened annually by computed tomography (CT) for UTUC. Results: Data for 1501 patients were reviewed. UTUC developed in 59 (4%) after a median of 20 months after HR-NMIBC. Most patients were symptomatic, but UTUC was discovered on routine follow-up imaging in 28%. On bivariate analysis, only multiple bladder tumors and the number of bladder recurrences were predictors for UTUC (P = 0.01 and P = 0.008, respectively). Multiple bladder tumors and ≥ 3 bladder recurrences remained significant on multivariable analysis. Conclusion: UTUC after HR-NMIBC is uncommon (4%). Despite routine follow-up CT imaging, recurrence was detected due to symptoms in most patients, and based on imaging only in 28%. Imaging surveillance can be prioritized in patients with multiple bladder tumors and those with ≥ 3 bladder recurrences. For the other patients, the benefit of imaging surveillance has to be weighed against the risks.