Endoscopic classifications as diagnostic factors of peptic ulcer and early gastric cancer - A possible reason why Helicobacter pylori infection causes gastric ulcers along lesser curvature

Background: Endoscopic classifications were reported to reflect the pathophysiology of gastric mucosa. However, relationship between gastric lesions and classifications has not been examined well. Aim: To investigate the relationship between endoscopic classifications and cancers or ulcers. Methods: In this study, 487 patients undergoing upper gastrointestinal endoscopy in Takahashi Clinic and 257 patients with early gastric cancer in Keio University Hospital were enrolled. Results: Incidence of reflux oesophagitis was higher in Helicobacter pylori-negative patients. K-form was better in the H. pylori-positive patients. Most cancers in the patients with the closed-type or reflux oesophagitis were of undifferentiated types. Incidences of ulcers were highest in C-2 and C-3 in which the borders of atrophy cross the medial oblique muscle bundle, the border circular muscle bundle or both, and 94% of ulcers in C-2 and C-3 stomach were located along the lesser curvature. Conclusion: The predominant existence of undifferentiated types in patients with reflux oesophagitis or closed-type stomach can be useful information for early diagnosis of cancers. The relationship between the Kimura-Takemoto classification and ulcer location may explain why H. pylori infection is related to ulcer formation along the lesser curvature.