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World J Gastroenterol. Feb 7, 2020; 26(5): 466-477
Published online Feb 7, 2020. doi: 10.3748/wjg.v26.i5.466
Endoscopic Kyoto classification of Helicobacter pylori infection and gastric cancer risk diagnosis
Osamu Toyoshima, Toshihiro Nishizawa, Kazuhiko Koike
Osamu Toyoshima, Toshihiro Nishizawa, Department of Gastroenterology, Toyoshima Endoscopy Clinic, Tokyo 157-0066, Japan
Osamu Toyoshima, Kazuhiko Koike, Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
Toshihiro Nishizawa, Department of Gastroenterology and Hepatology, International University of Health and Welfare, Mita Hospital, Tokyo 108-8329, Japan
Author contributions: Toyoshima O reviewed the literature and wrote the article; Nishizawa T revised and edited the article; Koike K revised and approved the final article.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Osamu Toyoshima, MD, Director, Doctor, Department of Gastroenterology, Toyoshima Endoscopy Clinic, 6-17-5 Seijo, Setagaya-ku, Tokyo 157-0066, Japan. t@ichou.com
Received: December 30, 2019
Peer-review started: December 30, 2019
First decision: January 11, 2020
Revised: January 15, 2020
Accepted: January 19, 2020
Article in press: January 19, 2020
Published online: February 7, 2020
Abstract

Recent advances in endoscopic technology allow detailed observation of the gastric mucosa. Today, endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori (H. pylori) infection and evaluate gastric cancer risk. In 2013, the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification, a new grading system for endoscopic gastritis. The Kyoto classification organized endoscopic findings related to H. pylori infection. The Kyoto classification score is the sum of scores for five endoscopic findings (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness with or without regular arrangement of collecting venules) and ranges from 0 to 8. Atrophy, intestinal metaplasia, enlarged folds, and nodularity contribute to gastric cancer risk. Diffuse redness and regular arrangement of collecting venules are related to H. pylori infection status. In subjects without a history of H. pylori eradication, the infection rates in those with Kyoto scores of 0, 1, and ≥ 2 were 1.5%, 45%, and 82%, respectively. A Kyoto classification score of 0 indicates no H. pylori infection. A Kyoto classification score of 2 or more indicates H. pylori infection. Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8, respectively. A Kyoto classification score of 4 or more might indicate gastric cancer risk.

Keywords: Gastric cancer, Helicobacter pylori, Endoscopy, Kyoto classification, Atrophy, Intestinal metaplasia, Enlarged fold, Nodularity, Diffuse redness, Regular arrangement of collecting venules

Core tip: The Kyoto classification organizes endoscopic findings based on Helicobacter pylori (H. pylori) infection. The score of the Kyoto classification is the sum of scores of five endoscopic findings (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness with or without regular arrangement of collecting venules) and ranges from 0 to 8. A high score is believed to reflect a higher risk of current H. pylori infection and gastric cancer. A Kyoto classification score of 0 indicates no H. pylori infection. A Kyoto classification score of ≥ 2 indicates current H. pylori infection. A Kyoto classification score of ≥ 4 might indicate gastric cancer risk.