Risk of colorectal cancer in chronic kidney disease: A matched cohort study based on administrative data

Background: The risk of colorectal cancer (CRC) in chronic kidney disease (CKD) patients relative to the general population is unknown. The aim of this population-based study was to investigate the risk of CRC in patients with CKD. Methods: The study cohort included patients aged ≥18 years diagnosed with CKD between 2004 and 2005 (n = 15,975). The comparison cohort (n = 79,875) included five randomly selected age- and gender-matched controls for each patient in the study cohort. All the subjects were followed up from the date of cohort entry until they developed CRC or until the end of 2006. Results: We identified 15,975 patients with a diagnosis of CKD who matched the inclusion criteria. A total of 460 patients developed CRC during the study period, of whom 116 were from the CKD cohort and 344 were from the comparison cohort. After adjusting for potential confounding factors, the CKD patients not undergoing dialysis were independently associated with a greater risk of CRC (hazard ratio, 1.79; 95 % confidence interval [CI] 1.41-2.27). The overall incidence rate of CRC was 341 per 100,000 person-years for CKD patients not undergoing dialysis, compared to 174 per 100,000 person-years. The age-matched hazard ratio of CRC after excluding dialysis patients was 1.64 (95 % CI 1.27-2.11) in patients 50 years and older, and 3.7 (95 % CI 1.83-7.49) in patients younger than 50 years. Conclusions: This population-based cohort study indicated that CKD patients not requiring dialysis have an increased risk of CRC compared to the general population, independent of comorbidities.