World Congress of Gastroenterology

WCOG 2019

The risk of colorectal cancer in patients with inflammatory bowel disease: a systematic review and meta-analysis
Weijie Zhou 1 Hao Chen 1 Weihong Sha 1


Inflammatory bowel disease (IBD) is associated with a high risk of colorectal cancer (CRC). However, previous studies have not reported the worldwide risk of CRC in IBD and the incidence of different stratification. This meta-analysis aims to estimate the worldwide risk and explore the incidence in different stratification.

Materials and Methods:

A literature search on Medline and Pubmed databases was conducted using terms related to CRC in IBD from inception to 2018. Overall incidence rate of CRC were obtained using a random-effects model as well as a cumulative risk data at 10 years, 20 years, and 30 years of the disease. Subgroup analysis was conducted to explore the incidence in different stratification.


Of 3620 studies, 46 articles were included and the total number of patients with IBD was 142190, in which 38672 had Crohns disease (CD) and 103518 had ulcerative colitis (UC). The overall prevalence of CRC was estimated to be 1.17% (95% CI 1.03-1.31%). Subgroup analysis by stratifying the studies according to the region, IBD type and tumor site revealed significant difference. The risk of CRC was 0.91% (95% CI 0.631.20%) at 10 years, 3.66% (95% 2.424.90%) at 20 years, and 12.58% (95% CI 5.9219.23%) at 30 years after IBD diagnosis.


We found that the worldwide incidence of CRC in IBD was low and the highest incidence rate was recorded in Australia among 5 continents. Patients with UC had a higher risk of CRC than those with CD. In both UC and CD, the colon was more susceptible to developing CRC.


inflammatory bowel disease; colorectal cancer; incidence