Long-term Risk of Advanced Neoplasia After Colonic Low-grade Dysplasia in Patients With Inflammatory Bowel Disease: A Nationwide Cohort Study

BACKGROUND AND AIMS

The long-term risk of high-grade dysplasia [HGD] and colorectal cancer [CRC] following low-grade dysplasia [LGD] in inflammatory bowel disease [IBD] patients is relatively unknown. We aimed to determine the long-term cumulative incidence of advanced neoplasia [HGD and/or CRC], and to identify risk factors for advanced neoplasia in a nationwide IBD cohort with a history of LGD.

METHODS

This is a nationwide cohort study using data from the Dutch National Pathology Registry [PALGA] to identify all IBD patients with LGD between 1991 and 2010 in the Netherlands. Follow-up data were collected until January 2016. We determined the cumulative incidence of advanced neoplasia and identified risk factors via multivariable Cox regression analysis.

RESULTS

We identified 4284 patients with colonic LGD with a median follow-up of 6.4 years after initial LGD diagnosis. The cumulative incidence of subsequent advanced neoplasia was 3.6, 8.5, 14.4 and 21.7%, after 1, 5, 10 and 15 years, respectively. The median time to develop advanced neoplasia after LGD was 3.6 years. Older age [≥ 55 years] at moment of LGD (hazard ratio [HR] 1.73, 95% confidence interval [CI] 1.44-2.06), male sex [HR 1.33, 95% CI 1.10-1.60], and follow-up at an academic [vs non-academic] medical centre [HR 1.37, 95% CI 1.07-1.76] were independent risk factors for advanced neoplasia following LGD.

CONCLUSIONS

In a large nationwide cohort with long-term follow-up of IBD patients with LGD, the cumulative incidence of advanced neoplasia was 21.7% after 15 years. Older age at LGD [≥55 years], male sex and follow-up by a tertiary IBD referral centre were independent risk factors for advanced neoplasia development after initial LGD.