The accuracy of polyp assessment during colonoscopy in FIT-screening is not acceptable on a routine basis
submitted 25 May 2014
accepted after revision 22 April 2014
23 June 2014 (online)
Background: During colonoscopy, correct assessment of polyps is important. Recognition of early carcinomas is needed for tailor-made treatment and avoidance of unnecessary complications. Moreover, accurate diagnosis of diminutive lesions could result in a safe resect and discard strategy. We assessed the accuracy of polyp assessment by general endoscopists without specific training or experience in image-enhanced endoscopy during routine colonoscopies within a fecal immunochemical test (FIT)-based screening program.
Methods: Data were collected in the third round of a FIT-based colorectal cancer screening pilot program. Patients diagnosed as FIT-positive (318) underwent colonoscopy using Olympus (160 and 180 series) endoscopes without magnification or routine use of (virtual) chromoendoscopy. Endoscopists received no special training. They made an on-site evaluation and classified detected polyps as hyperplastic, adenoma, carcinoma. Samples of resected lesions were sent for histopathology. Sensitivity and specificity were calculated. We differentiated for fellows and consultants.
Results: In the 318 patients with a positive FIT-screening result, 683 lesions were detected; 564 lesions were included in the analyses. The pathologist classified these lesions as 141 hyperplastic polyps, 349 adenomas, 16 carcinomas, and 58 other. Sensitivity for diagnosis of adenomas was 88 % (95 %CI 84 – 91); specificity 49 % (95 %CI 42 – 55). Of the 16 colorectal carcinomas, endoscopists diagnosed four incorrectly (sensitivity 75 % [95 %CI 44 – 89]; specificity 99 % [95 %CI 98 – 100]), including three stage I cancers and one stage III cancer. There were no differences in accuracy of diagnosis that related to different sizes of lesions or the experience of the endoscopist.
Conclusion: In a routine FIT-based screening setting and without specific training or routine use of (digital) chromoendoscopy, endoscopic prediction of the histopathology of colonic lesions is inaccurate when the procedure is performed by general endoscopists.
1 Funding: The study was supported by a grant from The Netherlands Organization for Health Research and Development of the Dutch Ministry of Health (ZonMW 12010095420).
- 1 Ferlay J, Parkin DM, Steliarova-Foucher E. Estimates of cancer incidence and mortality in Europe in 2008. Eur J Cancer 2010; 46: 765-781
- 2 Stegeman I, de Wijkerslooth TR, Mallant-Hent RC et al. Implementation of population screening for colorectal cancer by repeated Fecal Immunochemical Test (FIT): third round. BMC Gastroenterol 2012; 12: 73
- 3 Zafar A, Mustafa M, Chapman M. Colorectal polyps: when should we tattoo?. Surgical Endoscopy 2012; 26: 3264-3266
- 4 Denters MJ, Deutekom M, Fockens P et al. Implementation of population screening for colorectal cancer by repeated fecal occult blood test in the Netherlands. BMC Gastroenterol 2009; 9: 28
- 5 Ignjatovic A, Thomas-Gibson S, East JE et al. Development and validation of a training module on the use of narrow-band imaging in differentiation of small adenomas from hyperplastic colorectal polyps. Gastrointestinal Endoscopy 2011; 73: 128-133
- 6 Kuiper T, Marsman WA, Jansen JM et al. Accuracy for optical diagnosis of small colorectal polyps in nonacademic settings. Clin Gastroenterol Hepatol 2012; 10: 1016-1020
- 7 Schlemper RJ, Riddell RH, Kato Y et al. The Vienna classification of gastrointestinal epithelial neoplasia. Gut 2000; 47: 251-255
- 8 Rex DK, Kahi C, O’Brien M et al. The American Society for Gastrointestinal Endoscopy PIVI (Preservation and Incorporation of Valuable Endoscopic Innovations) on real-time endoscopic assessment of the histology of diminutive colorectal polyps. Gastrointest Endosc 2011; 73: 419-422
- 9 Dashwood RH. Early detection and prevention of colorectal cancer (review). Oncol Rep 1999; 6: 277-281
- 10 Rex DK. Narrow-band imaging without optical magnification for histologic analysis of colorectal polyps. Gastroenterology 2009; 136: 1174-1181
- 11 Ladabaum U, Fioritto A, Mitani A et al. Real-time optical biopsy of colon polyps with narrow band imaging in community practice does not yet meet key thresholds for clinical decisions. Gastroenterology 2013; 144: 81-91
- 12 Hewett DG, Kaltenbach T, Sano Y et al. Validation of a simple classification system for endoscopic diagnosis of small colorectal polyps using narrow-band imaging. Gastroenterology 2012; 143: 599-607.e1
- 13 Hayashi N, Tanaka S, Hewett DG et al. Endoscopic prediction of deep submucosal invasive carcinoma: validation of the narrow-band imaging international colorectal endoscopic (NICE) classification. Gastrointestinal Endoscopy 2013; 78: 625-632
- 14 Rastogi A, Keighley J, Singh V et al. High accuracy of narrow band imaging without magnification for the real-time characterization of polyp histology and its comparison with high-definition white light colonoscopy: a prospective study. Am J Gastroenterology 2009; 104: 2422-2430
- 15 Ignjatovic A, East JE, Suzuki N et al. Optical diagnosis of small colorectal polyps at routine colonoscopy (Detect InSpect ChAracterise Resect and Discard; DISCARD trial): a prospective cohort study. Lancet Oncol 2009; 10: 1171-1178
- 16 RIVM. Protocol for the authorization and auditing of colonoscopy centres and endoscopists. 2012: 1-68 Available from: http://www.rivm.nl/Bibliotheek/Professioneel_Praktisch/Protocollen/Preventie_Ziekte_Zorg/Darmkanker/Protocol_voor_de_toelating_en_auditing_van_coloscopiecentra_en_endoscopisten
- 17 Butterly LF, Chase MP, Pohl H et al. Prevalence of clinically important histology in small adenomas. Clinical gastroenterol hepatol 2006; 4: 343-348
- 18 Wanders LK, East JE, Uitentuis SE et al. Diagnostic performance of narrowed spectrum endoscopy, autofluorescence imaging, and confocal laser endomicroscopy for optical diagnosis of colonic polyps: a meta-analysis. Lancet Oncol 2013; 14: 1337-1347
- 19 Tanaka S, Sano Y. Aim to unify the narrow band imaging (NBI) magnifying classification for colorectal tumors: current status in Japan from a summary of the consensus symposium in the 79th Annual Meeting of the Japan Gastroenterological Endoscopy Society. Dig Endosc 2011; 23: 131-139