Anti-diabetic medications and the risk for colorectal cancer: A population-based nested case-control study

To evaluate whether anti-diabetic medications are related to colorectal cancer (CRC) risk in type 2 diabetes patients.The study was performed from a population-based prospective cohort provided by the National Health Insurance Corporation (2007-2014). Among the 2,084,602 patients newly diagnosed as type 2 diabetes in this period, the cases had incident CRC identified at least 3 years after the diagnosis, and the controls were matched to each case by age, sex, body mass index (BMI), fasting plasma glucose level, and year of the diagnosis. Conditional logistic regression was used to calculate the adjusted odds ratio (aOR) and its 95 % confidence intervals (CIs) for CRC by anti-diabetic medications.A total of 4,228 cases were identified and 4,228 controls were matched to the cases. Sulfonylurea use increased the risk for CRC [aOR (95 % CI), 1.14 (1.05-1.25)], showing an increasing trend with increasing cumulative doses (p for trend = 0.0008). In subgroup analysis, sulfonylurea use increased the CRC risk in DM patients ≥ 65 years, but not in the patients < 65 years. Among sulfonylurea drugs, gliclazide decreased the CRC risk [0.85 (0.72-1.00), p < 0.05], whereas glimepiride increased the risk significantly [1.14 (1.06-1.22)]. In contrast, metformin, meglitide, thiazolidinedione, dipeptidyl peptidase-4 inhibitors, and α-glucosidase inhibitor use did not modify the CRC risk.Our results suggest that sulfonylureas except for gliclazide increase the CRC risk in type 2 diabetic patients. Long-term follow-up studies are necessary to clarify the association of newer anti-diabetic medications with the CRC incidence.