title: Prediction of Helicobacter pylori status by conventional endoscopy, narrow-band imaging magnifying endoscopy in stomach after endoscopic resection of gastric cancer.
abstract: BACKGROUND
  To reduce the incidence of metachronous gastric carcinoma after endoscopic resection of early gastric cancer, Helicobacter pylori eradication therapy has been endorsed. It is not unusual for such patients to be H. pylori negative after eradication or for other reasons. If it were possible to predict H. pylori status using endoscopy alone, it would be very useful in clinical practice. To clarify the accuracy of endoscopic judgment of H. pylori status, we evaluated it in the stomach after endoscopic submucosal dissection (ESD) of gastric cancer.
  
  
  METHODS
  Fifty-six patients treated by ESD were enrolled. The diagnostic criteria for H. pylori status by conventional endoscopy and narrow-band imaging (NBI)-magnifying endoscopy were decided, and H. pylori status was judged by two endoscopists. Based on the H. pylori stool antigen test as a diagnostic gold standard, conventional endoscopy and NBI-magnifying endoscopy were compared for their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Interobserver agreement was assessed in terms of κ value.
  
  
  RESULTS
  Interobserver agreement was moderate (0.56) for conventional endoscopy and substantial (0.77) for NBI-magnifying endoscopy. The sensitivity, specificity, PPV, and NPV were 0.79, 0.52, 0.70, and 0.63 for conventional endoscopy and 0.91, 0.83, 0.88, and 0.86 for NBI-magnifying endoscopy, respectively.
  
  
  CONCLUSIONS
  Prediction of H. pylori status using NBI-magnifying endoscopy is practical, and interobserver agreement is substantial.
authors.affiliation: Department of Gastroenterology, Niigata Prefectural Yoshida Hospital, Niigata, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Yagi
authors.forename: Akiko
authors.initials: A
authors.lastname: Saka
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Nozawa
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nakamura
mesh_terms: D003430:Cross-Sectional Studies; D005243:Feces / Q000382:microbiology; D005753:Gastric Mucosa / Q000473:pathology; D005773:Gastroscopy / Q000379:methods*; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000472:pathogenicity; D006801:Humans; D062048:Narrow Band Imaging / Q000379:methods*; D016609:Neoplasms, Second Primary / Q000517:prevention & control*; D011446:Prospective Studies; D013270:Stomach / Q000382:microbiology / Q000473:pathology / Q000502:physiology; D013274:Stomach Neoplasms / Q000382:microbiology* / Q000473:pathology / Q000601:surgery
keywords: Helicobacter pylori; chronic gastritis; gastric cancer; magnifying endoscopy; narrow-band imaging