Abstract
BACKGROUND/OBJECTIVES: Since 2013, eradication therapy for Helicobacter pylori gastritis (Hp-ET) has been covered by the National Health Insurance of Japan. Recently, the risk of post-eradication gastric cancer (pE-GC) has increased. pE-GC includes cancers that develop immediately and several years after Hp-ET. Therefore, we aimed to clarify the endoscopic and histological characteristics of late types of pE-GCs. METHOD: One hundred patients with differentiated cancers detected after Hp-ET who underwent endoscopic submucosal dissection from 2015 to 2023 were compared. Patients were divided into two groups; the immediate group (n = 69), with cancer detected within 6 years, and the delayed group (n = 31), with cancer detected within >6 years after Hp-ET. The background mucosa and tumor mucosa were examined individually. The endoscopic findings were as follows: enlarged folds, map-like redness, intermediate zone irregularity, and the presence of a regular arrangement of collecting venules and a light blue crest (background); an irregular surface structure, an irregular vascular pattern, an irregular surface pattern, and a gastritis-like appearance (tumor). The histological findings were as follows: a low remnant rate of the fundic glands, intestinal metaplasia (IM), crypt enlargement, and neutrophil infiltration (background); mosaicism, the elongation of noncancer ducts, and an overlying non-neoplastic epithelium (tumor). RESULTS: There was no significant difference regarding the background mucosa and tumor mucosa between the two groups. In the delayed group, the remnant rate of the fundic glands was 19.8 ± 15.6%, and IM was 87.1% (27/31). Further, 90.3% (28/31) of the patients exhibited persistent neutrophil infiltration. CONCLUSION: This study suggested that patients with a low remnant rate of the fundic gland and IM and persistent mucosal inflammation were at high risk for developing pE-GCs.