Endoscopic and Histological Characteristics of Gastric Cancer Detected Long After Helicobacter pylori Eradication Therapy.

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.