Occurrence of Colorectal Cancer After a Negative Colonoscopy in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis.

Background/aim: Despite the application of colorectal cancer (CRC) surveillance guidelines, the detection of early neoplastic lesions might be difficult in patients with inflammatory bowel disease (IBD). To explore the risk of post-colonoscopy CRC (PCCRC) in patients with IBD we performed a systematic review and meta-analysis.

Patients And Methods: A systematic literature search was performed (PROSPERO; no. CRD42023453049). We included studies reporting the 3-year PCCRC (PCCRC-3y) prevalence, according to World Endoscopy Organization (WEO)-endorsed definition, in IBD and non-IBD patients. As primary outcome we evaluated the PCCRC-3y prevalence, according to WEO definitions, in IBD- and non-IBD patients and calculated the odds ratio (OR). The secondary outcome was to assess risk factors for PCCRC development in IBD patients.

Results: Three retrospective observational cohort studies were included. The pooled PCCRC-3y rate in patients with IBD was 30.8% [95% confidence interval (CI)=24.4-37.5%] and in non-IBD patients was 6.8% (95%CI=6.2-7.4%). The PCCRC-3y occurrence in IBD patients was significantly higher than that in non-IBD patients (OR=6.04; 95%CI=4.04-9.4; I=95%), but a high heterogeneity among studies was noted. Furthermore, patients with ulcerative colitis (UC) had a significantly higher prevalence of PCCRC than patients with Crohn's Disease (CD): 30.9% (95%CI=27.8-34.2%) vs. 22.3% (95%CI=18-27%), respectively (OR=1.6, 95%CI=1.2-2.2; I=0%).

Conclusion: One-third of CRC in IBD patients were PCCRC, and these numbers were significantly higher when compared with those in non-IBD patients. Furthermore, the prevalence of PCCRC in patients with UC was higher compared to those with CD. However, prospective studies are required to better characterize risk factors for PCCRC development in patients with IBD.