Crohn's disease instead of UC might increase the risk of small bowel cancer.

We read with interest the study by Axelrad et al 1 which reported that Crohn’s disease (CD) and UC were associated with nearly ninefold and twofold increased risk of small bowel cancer (SBC), respectively. However, there were also two observational studies2 3 suggesting that UC was not associated with risk of SBC. Because epidemiological studies about IBD and risk of SBC were controversial, to better understand this issue, we conducted this meta-analysis. We searched the PubMed and Web of Science for relevant studies published before 1 June 2020. We included observational studies investigating the associations between IBD and risk of SBC (including adenocarcinoma, neuroendocrine tumour and sarcoma) and reporting the HR, OR or other measures of association. The pooled OR and 95% CIs were estimated with random-effect model when the significant …