Risk Factors for Colorectal Cancer in Patients With Inflammatory Bowel Disease Undergoing Surveillance: a Prospective Cohort Study

Both ulcerative colitis and Crohn's colitis are associated with an increased risk of developing colorectal cancer (CRC). Although the increased risk of CRC in colitis patients is well established, several studies show that the risk varies widely between patients, depending on the presence of risk factors. Recently, several of these risk factors were implemented in the updated British guidelines for surveillance which are now used to determine surveillance intervals in our center. The new guideline recommends stratification of patients in a high, medium or low risk group depending on the presence of clinical and endoscopic risk factors and to adjust the surveillance interval accordingly. Although these guidelines provide a first step towards an individualized surveillance regimen, current data regarding risk factors for IBD-associated CRC are solely based on retrospective studies. Prospective data on the phenotype and genotype reliably predicting the risk of CRC is needed to further optimize surveillance in the future.

Objectives:

1. To confirm established and identify new predictive factors for colorectal cancer in a prospective cohort of IBD patients undergoing regular surveillance. Dysplasia or colorectal cancer will be the primary outcome.
2. To provide evidence that mucosal healing results in a significant reduction of colorectal dysplasia/neoplasia in IBD patients and that this is associated with 5-ASA or anti-TNF maintenance therapy.
3. Study the expression of several tumor markers in biopsies, blood and faeces at baseline and determine whether expression of these markers can predict dysplasia or colorectal cancer development during follow-up.