Implementation of optical diagnosis with a “resect and discard” strategy in clinical practice: DISCARD3 study

Abstract

Optical diagnosis (OD) of polyps can be performed with advanced endoscopic imaging. For high-confidence diagnoses, a "resect and discard" strategy could offer significant histopathology time and cost savings. The implementation threshold is a≥90% OD-histology surveillance interval concordance. Here we assessed the OD learning curve and feasibility of a resect and discard strategy for≤5-mm and<10-mm polyps in a bowel cancer screening setting. In this prospective feasibility study, 8 bowel cancer screening endoscopists completed a validated OD training module and performed procedures. All<10-mm consecutive polyps had white-light and narrow-band images taken and were given high- or low-confidence diagnoses until 120 high-confidence≤5-mm polyp diagnoses had been performed. All polyps had standard histology. High-confidence OD errors underwent root-cause analysis. Histology and OD-derived surveillance intervals were calculated. Of 565 invited patients, 525 patients were included. A total of 1560<10-mm polyps underwent OD and were resected and retrieved (1329≤5mm and 231 6-9mm). There were no<10-mm polyp cancers. High-confidence OD was accurate in 81.5% of≤5-mm and 92.8% of 6-9-mm polyps. Sensitivity for OD of a≤5-mm adenoma was 93.0% with a positive predictive value of 90.8%. OD-histology surveillance interval concordance for≤5-mm OD was 91.3% (209/229) for U.S. Multi-Society Task Force, 98.3% (225/229) for European Society of Gastrointestinal Endoscopy, and 98.7% (226/229) for British Society of Gastroenterology guidelines, respectively. A resect and discard strategy for high-confidence≤5-mm polyp OD in a group of bowel cancer screening colonoscopists is feasible and safe, with performance exceeding the 90% surveillance interval concordance required for implementation in clinical practice. (Clinical trial registration number: NCT04710693.).