Predicting Outcome in Colonoscopic High-Risk Surveillance

Objective: Surveillance with colonoscopy in risk groups for colorectal cancer needs to be based on adequate selection of individuals to examine and a well-devised timing. To stratify the risk of finding neoplasia at colonoscopy a cohort with increased familial risk of colorectal cancer was studied. Design: Based on family history, 1203 individuals with an at least twofold increased risk of colorectal cancer were offered regular colonoscopies. The impact of different variables in the family history was assessed by logistic regression for the prevalence of adenomas and advanced adenomas.Findings at the first colonoscopy were assessed regarding the association with risk of future lesions. Results: The prevalence of advanced lesions, when controlling for age, was associated with the number of first-degree relatives with colorectal cancer, with an age below 50 in the youngest family-member with colorectal cancer, but not with gender. Family history had a low impact on the prevalence of simple adenomas. The risk of future advanced lesions was only associated with the prevalence of advanced lesions at the screening colonoscopy, whereas a finding of subsequent adenomas was associated with advanced lesions, adenomas and hyper plastic polyps. Conclusion: Adenomas and advanced lesions were not associated with the same risk factors. In this study the most important risk factors for advanced lesions, including cancer, were the number of first-degree relatives and a young family member with colorectal cancer. Findings of simple adenomas and hyper plastic polyps did not seem to be associated with subsequent advanced lesions.