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

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

Figure 1

Kimura-Takemoto classification of endoscopic atrophy. Atrophic borders are indicated by a dotted line. A: C1 (Atrophy is limited to the antrum); B: C2 (Atrophy is limited to the minor area of the lesser curvature of the body); C: C3 (Atrophy exists in the major area of the lesser curvature of the body but does not extend beyond the cardia); D: O1 (Atrophy extends to the fundus over the cardia. Atrophic border of the body lies between the lesser curvature and anterior wall); E: O2 (Atrophic border of the body lies on the anterior wall); F: O3 (Atrophy is widespread with the border between the anterior wall and greater curvature).

Figure 2

Endoscopic findings of Kyoto classification. A: Intestinal metaplasia; B: Map-like redness; C: Enlarged folds; D: Nodularity; E: Diffuse redness; F: Regular arrangement of collecting venules in weakly magnified image.