Clinical Features of Invasive Gastric Cancer Developed After Helicobacter pylori Eradication During Regular Endoscopic Surveillance.

Objectives: Gastric cancer (GC) may be diagnosed after Helicobacter pylori eradication, sometimes with submucosal invasion; however, its clinical features on regular endoscopic surveillance remain unclear. This study evaluated invasive GC's characteristics after H. pylori eradication during regular endoscopic surveillance by comparing them with intramucosal cancers.

Methods: This retrospective multicenter study across 14 institutions between 2001 and 2022 evaluated patients with GC with submucosal or deeper invasion after surgical or endoscopic resection (invasive GC), compared to patients with intramucosal GC from high-volume facilities. GC depth was analyzed using logistic regression (patient and mucosal factors as covariates), with significant factors explored in a subanalysis.

Results: In total, 116 of 413 patients with invasive GC and 189 of 545 with intramucosal GC were eligible for analysis. Invasive GC exhibited the following characteristics: (1) GC was a more common reason for H. pylori eradication (adjusted odds ratio [OR] 2.67; 95% confidence interval [CI] 1.25-5.69); (2) the upper third of the stomach was the more common site (OR 2.63; 95% CI 1.41-5.30); and (3) map-like redness (MLR) could not be confirmed (OR 4.12; 95% CI 2.53-6.69). Subgroup analysis suggested that GC with less MLR occurred more often in younger females (p < 0.004), showed antral intestinal metaplasia (p < 0.001), and was common in undifferentiated or mixed-type GC (p < 0.001).

Conclusions: Characteristic findings of invasive GC during regular endoscopic surveillance after H. pylori eradication were associated with less MLR, along with H. pylori eradication due to GC and the upper gastric lesion locations.