Missed Lesions and Interval Colorectal Cancers

Potential causes of interval colorectal cancers (CRCs) — those arising after negative colonoscopy findings or after colon polyps are removed — include missed lesions, incomplete polypectomy, and development of de novo cancers in patients without polyps.

To estimate risks for interval CRCs from missed lesions, investigators conducted a modeling study using data from the literature on adenoma miss rates, cancer prevalence (by polyp size) among adenoma patients, and available data estimating rates of adenoma-to-cancer transitions.

Applying the model to a hypothetical average-risk population, the researchers estimated that 0.7 per 1000 patients undergoing screening colonoscopy would have a cancer that was missed at baseline colonoscopy and that a…