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

Summary 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.