Evaluating the Use of Environmental and Polygenic Risk Scores to Inform Colorectal Cancer Risk-Based Surveillance Intervals

INTRODUCTION: United States Multi-Society Task Force colonoscopy surveillance intervals are based solely on adenoma characteristics, without accounting for other risk factors. We investigated whether a risk model including demographic, environmental, and genetic risk factors could individualize surveillance intervals under an “equal management of equal risks” framework. METHODS: Using 14,069 individuals from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial who had a diagnostic colonoscopy following an abnormal flexible sigmoidoscopy, we modeled the risk of colorectal cancer, considering the diagnostic colonoscopy finding, baseline risk factors (e.g., age and sex), 19 lifestyle and environmental risk factors, and a polygenic risk score for colorectal cancer. Ten-year absolute cancer risks for each diagnostic colonoscopy finding (advanced adenomas [N = 2,446], ≥3 non-advanced adenomas [N = 483], 1–2 non-advanced adenomas [N = 4,400], and no adenoma [N = 7,183]) were used as implicit risk thresholds for recommended surveillance intervals. RESULTS: The