Endoscopic Kyoto classification of Helicobacter pylori infection and gastric cancer risk diagnosis

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 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 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 infection status. In subjects without a history of 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 infection. A Kyoto classification score of 2 or more indicates 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.