title: Clinical impact and characteristics of the narrow-band imaging magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.
abstract: OBJECTIVE
  The Japan NBI Expert Team (JNET) was established in 2011 and has proposed a universal narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors. The aim of this study was to evaluate the clinical usefulness of the JNET classification for colorectal lesions.
  
  
  METHODS
  We analyzed 2933 colorectal lesions, which were diagnosed by NBI magnifying observation before endoscopic treatment or surgery. The colorectal lesions consisted of 136 hyperplastic polyps/sessile serrated polyps (HPs/SSPs), 1926 low-grade dysplasia (LGD), 571 high-grade dysplasia (HGD), 87 superficial submucosal invasive (SM-s) carcinomas, and 213 deep submucosal invasive (SM-d) carcinomas. We evaluated the relationship between the JNET classification and the histologic findings of these lesions.
  
  
  RESULTS
  The sensitivity, specificity, positive and negative predictive values, and accuracy of Type 1 lesions for the diagnosis of HP/SSP were, respectively, 87.5%, 99.9%, 97.5%, 99.4%, and 99.3%; of Type 2A lesions for the diagnosis of LGD were 74.3%, 92.7%, 98.3%, 38.7%, and 77.1%; of Type 2B lesions for the diagnosis of HGD/SM-s carcinoma were 61.9%, 82.8%, 50.9%, 88.2%, and 78.1%; for Type 3 lesions for the diagnosis of SM-d carcinoma were 55.4%, 99.8%, 95.2%, 96.6%, and 96.6%, respectively.
  
  
  CONCLUSIONS
  Types 1, 2A, and 3 of the JNET classification were very reliable indicators for HP/SSP, LGD, and SM-d carcinoma, respectively. However, the specificity and positive predictive value of Type 2B were relatively lower than those of others. Therefore, an additional examination such as pit pattern diagnosis using chromoagents is necessary for accurate diagnosis of Type 2B lesions.
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kyoku
authors.initials: K
authors.lastname: Sumimoto
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Shigita
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Hirano
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Tamaru
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ninomiya
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Asayama
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Nana
authors.initials: N
authors.lastname: Hayashi
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Oka
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Arihiro
authors.affiliation: Health Service Center, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshihara
authors.affiliation: Department of Gastroenterology and Metabolism, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D000069916:Endoscopic Mucosal Resection; D006801:Humans; D007564:Japan; D062048:Narrow Band Imaging; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012680:Sensitivity and Specificity