Comparison of the risks of renal cell carcinoma or urothelial cancer between hemodialysis and peritoneal dialysis patients

Purpose: This study is to compare risks of developing renal cell carcinoma or urothelial cancer between hemodialysis (HD) and peritoneal dialysis (PD) patients. Methods: The age-, sex-, and index year-matched patients with newly diagnosed end-stage kidney disease (ESKD) undergoing dialysis [HD (N = 22,587) or PD (N = 11,547)] from 2000 to 2015 in Taiwan were identified. Patients were followed until the development of renal cell carcinoma or urothelial cancer, renal transplantation, death, or the end of follow-up (December 31, 2017). The hazard ratio (HR), and sub-hazards ratio (SHR), in which death was considered as a competing risk, of developing renal cell carcinoma or urothelial cancer were compared between the HD and PD patients. Results: The incidence rate of renal cell carcinoma was higher in the PD group than in age-, sex-, and index year-matched HD group (11.5 versus 5.52 per 10,000 person-years), with an adjusted HR of 2.15 (95% confidence interval (CI) = 1.59, 2.92), and an adjusted SHR of 1.97 (95% CI = 1.46, 2.67). The incidence rate of urothelial cancer was also higher in the PD group than in corresponding HD group (40.3 and 34.0 per 10,000 person-years), with an adjusted HR of 1.15 (95% CI = 1.00, 1.33) and an adjusted SHR of 1.08 (95% CI = 0.94, 1.25). These findings were further validated in propensity score-matched dialysis cohorts. Conclusions: ESKD patients undergoing PD are at a higher risk of developing renal cell carcinoma than those on HD, but risks of developing urothelial cancer are similar among the two groups.