Teaching Six ‘Blink’ Features Reduces General Endoscopists’ Cancer Miss-Rate in Image-Based Assessment of Large Colorectal Polyps

Background&Aims: Accurate cancer detection in large non-pedunculated colorectal polyps (LNPCPs) remains challenging for general endoscopists. We evaluated whether teaching six gross morphological "Blink" features could improve the accuracy of cancer detection. Methods: This prospective interventional study assessed general endoscopists evaluating 20 LNPCP images (7 with histologically-confirmed submucosal invasive cancer including 4 deep invasions ≥1000µm, 13 benign). Participants assessed images before and after a 2-minute educational video introducing six Blink features: spontaneous bleeding, depression, fold deformation, extra redness, ulceration, and chicken-skin mucosa. Primary outcome was change in miss-rate for cancer detection. Generalized linear mixed models accounted for clustering within raters and polyps. Results: 165 participants included gastroenterology consultants (63.6%), trainees (21.2%), students (1.8%) and colorectal surgeons (13.3%) with a median colonoscopy experience of 6.5 years. Post-intervention the cancer miss-rate decreased four-fold from 26.6% (95%CI 13.4-46.0) to 5.7%(95%CI 2.4-12.8). This improvement was consistent across experience levels. The false alarm rate increased less-than two-fold from 25.0% (95%CI 15.1-38.5) to 42.2%(95%CI 27.7-58.2). Multivariable analysis identified spontaneous bleeding (OR 3.92, 95%CI 3.11-4.96), extra redness (OR 3.66, 95%CI 3.09-4.33), and depression (OR 3.06, 95%CI 2.58-3.64) as independent predictors of cancer amongst general endoscopists. Mean Blink features per polyp were 1.08 (95%CI 0.82–1.40) for benign lesions versus 2.46 (95%CI 1.85–3.12) for cancers. Conclusions: Teaching six Blink features to general endoscopists led to a 4x reduction in cancer miss-rates in an image-based evaluation. While specificity decreased, this trade-off favors patient safety, as false-positives trigger established clinical safeguards while missed cancers risk inappropriate endoscopic resection with potentially irreversible consequences.