Gender and Age Differences of Genitourinary Cancers Among Chronic Dialysis Patients in Taiwan

Background: To investigate the age and gender differences among chronic dialysis patients who developed genitourinary cancers in Taiwan. Patients and Methods: Incident hemodialysis patients aged 20 years or older were selected for retrospective cohort study from the National Health Insurance Research Database between 2002 and 2015, and the Taiwan Cancer Registry Database between 2007 and 2015. A two-step approach was employed to find the respective matched controls of non-dialysis patients. Finally, 65,450 dialysis patients and 261,800 non-dialysis patients were matched for further analysis. New diagnosis of genitourinary cancers during follow-up was the primary outcome of interest. Results: Dialysis was significantly associated with increased risk of all types of genitourinary cancers (P <.001), substantially within the first two years after dialysis initiation. Cox proportional hazard analysis showed a significantly increased hazard ratio (HR 6.58, 95% CI 6.05-7.16) among dialysis patients after multivariate adjustment, and the highest risk was bladder cancer (HR 7.85, 95% CI 6.97-8.84). Subgroup analysis showed younger dialysis patients (20-49 years old) had the highest risk of genitourinary cancer, especially females, in this subgroup with the highest risk of bladder cancer (HR 58.08, 95% CI 13.88-243.06). Conclusion: The risks of all site-specific genitourinary cancers were increased in chronic dialysis patients, especially in younger females. Developing different screening strategies for these high-risk patients is necessary. This study compared the effect of sex, age and dialysis duration on the susceptibility to develop genitourinary cancers in dialysis patients through the national health database linkage in Taiwan. We matched 65,450 dialysis patients and 261,800 non-dialysis patients for further analysis. Younger and female dialysis patients were at higher risk of kidney and bladder cancers.