Teaching Six "blink" features reduces general endoscopist cancer miss rate in image-based assessment of large...

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 accuracy of cancer detection.

This prospective interventional study assessed general endoscopists evaluating 20 LNPCP images (7 with histologically confirmed submucosal invasive cancer including four deep invasions ≥ 1000 µm, 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.

The 165 participants included gastroenterology consultants (63.6%), trainees (21.2%), students (1.8%) and colorectal surgeons (13.3%) with median colonoscopy experience of 6.5 years. Post-intervention, the cancer miss rate decreased four-fold from 26.6% (95% confidence interval [CI] 13.4-46.0) to 5.7% (95% CI 2.4-12.8). The 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 (odds ratio [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 among general endoscopists. Mean blink features per polyp were 1.08 (95% CI 0.82-1.40) for benign lesions vs 2.46 (95% CI 1.85-3.12) for cancers.

Teaching six blink features to general endoscopists led to a four-times reduction in cancer miss rates in an image-based evaluation. Although specificity decreased, this trade-off favors patient safety because false positives trigger established clinical safeguards whereas missed cancers risk inappropriate endoscopic resection with potentially irreversible consequences.