To Örebro University

BACKGROUND: Individuals with inflammatory bowel disease (IBD) have an elevated risk of colorectal neoplasia (CRN), including colorectal dysplasia and cancer (CRC). Despite surveillance strategies to prevent CRC, the clinical course of dysplasia types remains poorly understood.

METHODS: We conducted a nationwide cohort study using the Swedish Patient Register and the ESPRESSO histopathology cohort to identify patients diagnosed with IBD between 1969 and 2023. Patients were classified according to their first (baseline) incident episode of dysplasia (no dysplasia, ND; indefinite, IND; low-grade, LGD; high-grade, HGD). Our primary outcome was future advanced CRN (HGD or CRC) during follow-up. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CI) were estimated using Cox regression.

RESULTS: We identified 54,534 patients with IBD, including 1,320 with a first (baseline) episode of dysplasia (264 IND, 1031 LGD, 25 HGD), and 53,214 with ND. Over a median follow-up of 13.3 years, 2.3% of ND patients had future advanced CRN compared to 5.3% of IND patients (aHR 1.85, 95% CI 1.09-3.15) and 8.3% of LGD patients (aHR 3.51, 95% CI 2.77-4.45). Of those with HGD, 40% developed CRC (aHR 47.88, 95% CI 25.53-89.80). Risk factors for future dysplasia included male sex, younger age at diagnosis, extensive colitis, primary sclerosing cholangitis, and histologic inflammation.

CONCLUSION: Patients with IBD and dysplasia have a significantly increased risk of future dysplasia, particularly among patients with HGD. Personalized surveillance strategies based on risk factors are critical for preventing advanced CRN.