Dialysis Increases the Risk of Bladder Recurrence in Patients with Upper Tract Urothelial Cancer: A Population-Based Study

The relation of dialysis to tumor recurrence in patients with upper tract urothelial cancer (UTUC) is unknown; however, a limited number of small-scale studies suggest that patients with renal diseases prior to UTUC are more likely to exhibit bladder recurrence. We performed a population-based analysis to determine the effect of dialysis on bladder recurrence for patients with UTUC. This retrospective cohort study included patients diagnosed with UTUC (2002-2007) from the Taiwan National Cancer Registry and divided them into two groups-dialysis and non-dialysis groups. These patients were followed up until bladder recurrence, death, or the end of 2010. Competing risk analyses adjusting covariates and death were applied to determine the relation of dialysis and bladder recurrence. Of the 5141 eligible patients, 548 (10.7%) were undergoing dialysis. The cumulative bladder recurrence was significantly higher in the dialysis group than in the non-dialysis group (29% vs. 21%, modified log-rank p < 0.001). In the multivariable analysis, the dialysis group exhibited a 64% increased bladder recurrence risk (cause-specific hazard ratio 1.64, 95% confidence interval 1.34-2.01, p < 0.001), which was confirmed using stratification and propensity score weighting methods. The other prognostic factors for bladder recurrence were sex, diabetes, cardiac disorder, Charlson Comorbidity Index, and tumor grade. Despite unknown reasons, approximately one-tenth of patients with UTUC have experienced dialysis treatment. Patients undergoing dialysis have a higher risk of bladder recurrence. Various treatment and screening strategies should be developed for dialysis and non-dialysis patients.