Increased Risk of Colorectal Cancer in Patients With Celiac Disease: A Population-Based Study

Background and aim: The association between celiac disease (CD) and the development of small bowel lymphoproliferative disorders and esophageal adenocarcinoma has been established in the literature. However, there is only a little evidence demonstrating an increased risk of colorectal cancer (CRC) in patients with CD. Hence, we conducted a cross-sectional population-based study to evaluate the risk of developing CRC in patients who have had a diagnosis of CD. Methodology: We used a commercial database (Explorys Inc, Cleveland, OH), which includes electronic health records from 26 major integrated US healthcare systems. Patients aged 18-65 years were included. Patients with inflammatory bowel disease (IBD) were excluded. Multivariate analysis using backward stepwise logistic regression was performed to calculate the risk of developing CRC in potential confounders. A two-sided P-value <0.05 was considered statistically significant. Results: 79,843,332 individuals were screened in the database and 47,400,960 were selected in the final analysis after accounting for inclusion and exclusion criteria. Using a stepwise multivariate regression analysis, the odds of having CRC among patients with CD was 10.18 (95% CI 9.72-10.65) (P-value <0.001). The odds also remained high among males 1.49 (95% CI 1.36-1.63), African Americans 1.51 (95% CI 1.35-1.68), patients who have type 2 diabetes mellitus (T2DM) 2.71 (95% CI 2.66-2.76), are smokers 2.49 (95% CI 2.44-2.54), are obese 2.21 (95% CI 2.17-2.25), and are alcoholic 1.72 (95% CI 1.66-1.78). Conclusion: Our study demonstrates that patients with CD are frequently found to have CRC even when adjusting for common risk factors. This adds to the literature and helps spread awareness to clinicians that the effects of CD are not only limited to the small bowel as the disease tends to involve other parts of the gastrointestinal tract also, especially the colon. The threshold to screen patients with CD should be considered to be lowered.