Real-world retrospective cohort study of inflammatory bowel disease colorectal cancer surveillance

Objective Inflammatory bowel disease (IBD) colorectal cancer (CRC) surveillance aims to reduce cancer-associated mortality. We report outcomes of IBD-CRC colonoscopy surveillance, highlight missed surveillance opportunities and identify factors associated with dysplasia and CRC over a 10-year period at our centre. Methods Endoscopy software was interrogated for ‘IBD surveillance’ procedures from April 2008 to December 2018, to capture the surveillance cohort. Local databases were searched for all IBD-CRC cases outside surveillance. Follow-up was until August 2024. Results 1892 IBD surveillance colonoscopies from 1262 patients identified 144 cases of dysplasia (105/1892 sporadic; 16/1892 IBD-associated; 7/1892 indefinite for IBD-dysplasia; 16/1892 unspecified dysplasia aetiology). IBD-CRC was rare at 0.75 cases per 1000 patient years. Of the 21 IBD-CRC cases identified in this cohort, 8 were appropriately surveillance-detected within their correct surveillance interval. Of the remaining 13 cancers detected by other means, 7 were overdue surveillance. Factors associated with developing cancer were prior dysplasia (OR 10.84, 95% CI 4.46 to 26.36) (p<0.001), inflammatory pseudopolyps (OR 4.32, 95% CI 1.78 to 10.44) (p=0.001) and IBD disease duration (OR 1.04, 95% CI 1.002 to 1.08) (p=0.036). The 3-year postcolonoscopy CRC rate was 14.3%. Outside this surveillance cohort, 43 additional IBD-CRCs were identified; patients were more likely to have Crohn’s disease (p=0.040) and shorter disease duration (p<0.001). Cancer stage at presentation (p=0.609) and overall survival (p=0.679) was not different between the surveillance and non-surveillance cohorts. Conclusions In this real-world cohort, active surveillance did not improve cancer survival compared with patients whose cancer was detected by other means. A modern approach is needed to maximise the potential benefits of surveillance.