Accuracy of narrow-band imaging in predicting colonoscopy surveillance intervals and histology of distal diminutive polyps: Results from a multicenter, prospective trial

Background: In vivo prediction of colorectal polyp histology by narrow-band imaging (NBI) could potentially avoid post-polypectomy histologic examination or resection of diminutive lesions, thereby reducing costs and risk. Objective: To assess whether NBI is able to predict colonoscopy surveillance intervals and histology of distal diminutive polyps according to American Society for Gastrointestinal Endoscopy (ASGE) criteria. Design: Prospective, multicenter study. Setting: Five endoscopic centers. Patients: Consecutive patients undergoing colonoscopy in 5 centers were included. Intervention: Participating endoscopists were required to pass a before-study qualifying examination. Histology of polyps that were <10 mm was predicted at NBI and assigned a designation of high or low confidence. Main Outcome Measurements: Accuracy of high-confidence NBI prediction for polyps ≤5 mm in predicting surveillance intervals and negative predictive value (NPV) for adenomatous histology in the rectosigmoid colon were compared with the ASGE thresholds (90% agreement, 90% NPV). Results: A total of 278 patients (mean age, 63 years; 58% male) were enrolled. At colonoscopy, 574 (97.3%) polyps <10 mm (429 ≤5 mm, 60% adenomatous) were retrieved for histologic analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of high confidence-NBI predictions for adenomatous histology in lesions ≤5 mm were 90%, 88%, 89%, 89%, and 89%, respectively. High-confidence characterization of polyps ≤5 mm predicted the correct surveillance interval in 92% to 99% of cases, according to the American and European guidelines. NPV of high-confidence NBI for adenomatous histology for the rectosigmoid colon lesions ≤5 mm was 92%. Limitations: Only experienced endoscopists were included. Conclusion: High-confidence prediction of histology for polyps ≤5 mm appears to be sufficiently accurate to avoid post-polypectomy histologic examination of the resected lesions as well as to allow rectosigmoid hyperplastic polyps to be left in place without resection. (Clinical trial registration number: NCT01675752.)