Predicting Who Needs Screening Colonoscopy

Previous attempts to model risk stratification for colorectal cancer have insufficiently discriminated risk among patients, making them not useful in clinical practice. In the current study, investigators modeled risk based on age, sex, waist circumference, smoking history, and family history of colorectal cancer.

In a derivation sample of 2993 patients aged 50 to 80 years undergoing their first screening colonoscopy, the risks for advanced neoplasia were as follows across risk groups: very low, 1.9%; low, 4.9%; intermediate, 9.9%, and high, 24.9%. Fifty-one of 70 advanced neoplasms, including 5 cancers in the 2 lowest-risk groups, were within reach of sigmoidoscopy passed to the descending colon. In a validation sample of 1467 patients, the…