BACKGROUND:

The occurrence of inflammatory bowel disease (IBD) is higher in Western countries and is increasing worldwide. The incidence of IBDs is about nearly 20-fold in Western countries than Asia and has risen in Taiwan over the past few decades. Epidemiological studies have demonstrated an increased risk of colorectal cancer (CRC) in patients with IBD. The prevalence of IBD as well as IBD-associated CRC is changing and the risk of CRC in patients with IBD appears to be greater in Western countries, but CRC risk in IBD patients is less well understood in low endemic areas, such as Asia.

METHODS:

This population-based cohort study collected data from the Taiwan Health Insurance Research Database (from January 1998 to December 2011). In total, 10 650 patients with confirmed diagnosis of IBD served as the IBD cohort and 42 600 non-IBD subjects were enrolled. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) were used to assess the risk of CRC.

RESULTS:

The incidence of CRC was slightly lower in the IBD cohort compared with that in the non-IBD cohort (0.94 vs. 1.13 per 1000 person-years), with an adjusted HR of 0.99 (95% CI: 0.71-1.37). More than four hospitalizations were associated with a significantly higher risk of CRC in IBD patients in the Cox model (adjusted HR = 3.48, 95% CI: 1.59-7.63).

CONCLUSIONS:

The risk for CRC was not increased among IBD patients overall, but appeared to be increased with cumulative frequency of hospitalizations for IBD.