Cancer Incidence and Mortality in Chronic Dialysis Population: A Multicenter Cohort Study.

BACKGROUND: Different studies in the past have shown that the risk of cancer development is increased in chronic dialysis patients. However, data concerning the cancer risk in Asian dialysis patients was scarce. More importantly, there was lack of information about the cancer-specific mortality in dialysis patients.

METHODS: A multicenter retrospective cohort study of 6,254 patients who started either chronic peritoneal dialysis or hemodialysis between 1994 and 2014 in 4 renal units in Hong Kong. Patterns of cancer incidence and mortality in our dialysis patients were compared with those of the general population using standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) respectively.

RESULTS: With 14,887 person-years of follow-up, 220 cancers were recorded. The SIR of all cancers was 1.44 (95% CI 1.26-1.65). A trend of an increased SIR was observed in young patients and within the first year of dialysis. Colorectum was the most common site of cancer (20%) while kidney cancer carried the highest risk (SIR 12.28, 95% CI 8.44-17.08). The SMR of all cancers was 0.91 (95% CI 0.72-1.13) and only kidney cancer had higher cancer mortality risk (SMR 4.92, 95% CI 1.80-10.70). SMR was highest in young patients and then decreased with age.

CONCLUSIONS: The incidence of cancers in our chronic dialysis patients was elevated. Our findings of substantially increased risks in young patients, particularly in relation to kidney cancer, suggest that we can adopt a more individualized approach to cancer screening in chronic dialysis patients.