Narrow band imaging optical diagnosis of small colorectal polyps in routine clinical practice: the Detect Inspect Characterise Resect and Discard 2 (DISCARD 2) study. Issue 5 (19th April 2016)

• Record Type: Journal Article
• Authors: Rees, Colin J; Rajasekhar, Praveen T; Wilson, Ana; Close, Helen; Rutter, Matthew D; Saunders, Brian P; East, James E; Maier, Rebecca; Moorghen, Morgan; Muhammad, Usman; Hancock, Helen; Jayaprakash, Anthoor; MacDonald, Chris; Ramadas, Arvind; Dhar, Anjan; Mason, James M
• Other Names: Neilson Laura author non-byline.; Ahmed Adil author non-byline.; Bevan Roisin author non-byline.; Bradburn Mike author non-byline.; Butt Faheem author non-byline.; Douglass Andrew author non-byline.; Edge Vikki author non-byline.; Greenaway John author non-byline.; Gregory Wendy author non-byline.; Hancock John author non-byline.; Hurst Lindsay author non-byline.; Javaid Babur author non-byline.; Joy Diamond author non-byline.; Kejariwal Deepak author non-byline.; McConnell Susan author non-byline.; Miles Jestina author non-byline.; Mills Sarah author non-byline.; Oliver David author non-byline.; Panter Simon author non-byline.; Porras-Perez Francisco author non-byline.; Silcock John author non-byline.; Topping Joanne author non-byline.; Wells Christopher author non-byline.; Wilkinson Jennifer author non-byline.; Frost Catherine author non-byline.; Rubin Greg author non-byline.; Mulley Janice author non-byline.; Yiannakou Yan author non-byline.; Attwood Stephen author non-byline.; Bramble Mike author non-byline.; Kasim Adetayo author non-byline.;
• Is Part Of: Gut. Volume 66:Issue 5(2017)
• Page Start: 887
• Page End: 895
• Publication Date: 2016-04-19
• Subjects: ENDOSCOPY -- COLONOSCOPY -- COLORECTAL ADENOMAS -- COLONIC NEOPLASMS; Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gutjnl-2015-310584
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : Background: Accurate optical characterisation and removal of small adenomas (<10 mm) at colonoscopy would allow hyperplastic polyps to be left in situ and surveillance intervals to be determined without the need for histopathology. Although accurate in specialist practice the performance of narrow band imaging (NBI), colonoscopy in routine clinical practice is poorly understood. Methods: NBI-assisted optical diagnosis was compared with reference standard histopathological findings in a prospective, blinded study, which recruited adults undergoing routine colonoscopy in six general hospitals in the UK. Participating colonoscopists (N=28) were trained using the NBI International Colorectal Endoscopic (NICE) classification (relating to colour, vessel structure and surface pattern). By comparing the optical and histological findings in patients with only small polyps, test sensitivity was determined at the patient level using two thresholds: presence of adenoma and need for surveillance. Accuracy of identifying adenomatous polyps <10 mm was compared at the polyp level using hierarchical models, allowing determinants of accuracy to be explored. Findings: Of 1688 patients recruited, 722 (42.8%) had polyps <10 mm with 567 (78.5%) having only polyps <10 mm. Test sensitivity (presence of adenoma, N=499 patients) by NBI optical diagnosis was 83.4% (95% CI 79.6% to 86.9%), significantly less than the 95% sensitivity (p<0.001) this study was powered to detect. Test sensitivity (need for surveillance) was 73.0% (95% CI 66.5% to 79.9%). Analysed at the polyp level, test sensitivity (presence of adenoma, N=1620 polyps) was 76.1% (95% CI 72.8% to 79.1%). In fully adjusted analyses, test sensitivity was 99.4% (95% CI 98.2% to 99.8%) if two or more NICE adenoma characteristics were identified. Neither colonoscopist expertise, confidence in diagnosis nor use of high definition colonoscopy independently improved test accuracy. Interpretation: This large multicentre study demonstrates that NBI optical diagnosis cannot currently be recommended for application in routine clinical practice. Further work is required to evaluate whether variation in test accuracy is related to polyp characteristics or colonoscopist training. Trial registration number: The study was registered with clinicaltrials.gov (NCT01603927 ).