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.