Objective The characteristics of gastric cancer in patients with atrophic mucosa and no apparent history of Helicobacter pylori eradication have not been thoroughly investigated. Therefore, this study examined the clinicopathological characteristics of gastric cancer in these patients. Methods We retrospectively examined the endoscopic and pathological characteristics of gastric cancer in patients who underwent endoscopic submucosal dissection. Patients We divided the patients into 2 groups: those with gastric atrophy and no history of eradication (group A
n=102) and those with a history of eradication (group B
n=161). In group A, patients were further divided into mild atrophy (group C) and severe atrophy (group D) groups, while group B was further divided into those who underwent eradication treatment >
5 years ago (group E) and those who underwent eradication 1-5 years ago (group F). Results Group A comprised significantly older individuals (75±8.0 vs. 71±7.5 years old, p<
0.001) with a higher frequency of elevated gastric cancer than group B (32.4% vs. 17.4%, p=0.006). Compared with group E, group A was older and had a greater incidence of elevated gastric cancer. The incidence of gastric cancer in the U or M region was lower in group C than in group D. Conclusion Gastric cancer in patients with gastric atrophy and no history of eradication was associated with an older age and higher frequency of elevated-type morphology than in those with a history of eradication.