Cancer Risk in the Early Stages of Inflammatory Bowel Disease in Korean Patients: A Nationwide Population-based Study.

BACKGROUND AND AIMS: The association between inflammatory bowel disease [IBD] and cancer remains poorly defined in Asian populations. Therefore, we conducted a nationwide population-based study to determine the cancer risk in Korean patients with IBD.

METHODS

Using the National Health Insurance claims data, we collected data on patients diagnosed with IBD (5595 Crohn's disease [CD] and 10 049 ulcerative colitis [UC]) from 2011 to 2014. Standardized incidence ratios [SIRs] of overall and site-specific cancers in IBD patients in comparison with the general population were calculated.

RESULTS

The overall cancer risk was higher in CD patients [SIR, 2.2; 95% confidence interval, 1.5-3.0 in men and 3.3; 2.4-4.5 in women] and UC patients [1.9; 1.6-2.3 in men and 1.9; 1.5-2.4 in women]. There were significantly increased risks for the following cancers: small bowel cancer [31.2; 3.8-112.8], colorectal cancer [CRC] [3.7; 1.6-7.2] and haematological cancer [4.0; 1.1-10.3] in men with CD; small bowel cancer [61.1; 7.4-220.6], CRC [4.7; 1.5-10.9], liver cancer [15.3; 5.6-33.2], pancreatic cancer [8.6; 1.0-31.0] and haematological cancer [11.0; 3.6-25.7] in women with CD; CRC [2.1; 1.3-3.3] and cancer of the prostate [3.5; 2.1-5.5], brain/central nervous system [6.1; 1.3-17.9] and thyroid [2.2; 1.1-3.9] in men with UC; and CRC [3.0; 1.5-5.3], cancer of the liver [4.4; 1.6-9.7] and cervix uteri [5.7; 2.4-11.1], and haematological cancer [3.5; 1.1-8.1] in women with UC. Women with CD had an increased risk of non-Hodgkin lymphoma [NHL] and leukaemia. Women with UC had an increased risk of NHL.

CONCLUSIONS

Korean patients with IBD are at increased risk for overall, intestinal and haematological cancer.