Characteristics of gastric cancers developed more than 10 years after eradication of Helicobacter pylori

Helicobacter pylori (H pylori) eradication is expected to effectively prevent gastric cancer (GC). However, GC cases may occur even longer than 10 years after H pylori eradication (L10AE). Moreover, the associated factors and characteristics are unknown. In this retrospective, single-center study conducted between 2017 and 2022, patients with GC diagnosed after H pylori eradication were enrolled and categorized into groups according to whether they were shorter than 10 years after H pylori eradication (S10AE) or L10AE. Patients were also categorized according to the depth of cancer invasion. Clinical data, pathological data, and risk factors were analyzed using logistic regression. Clinicopathological characteristics of GC diagnosed at L10AE and those invading the submucosal tissue or deeper (SMD) were investigated. In total, 202 cases of GC occurring after H pylori eradication were identified. Comparison of 158 S10AE and 44 L10AE GC cases revealed a significantly longer surveillance interval (SI) in L10AE cases (median: 2.0 vs 1.0 years, P = .01). Comparison of 150 intramucosal and 52 SMD GC cases revealed that L10AE GC cases were significantly more frequent amongst the SMD cases (18.0% vs 32.7%, P = .03). Pathologically, undifferentiated and mixed types were significantly more frequent in GC cases with SMD invasion (P < .001). Multivariate analysis revealed that L10AE was significantly related to GC cases with SMD invasion (odds ratio, 2.45; 95% confidence interval, 1.15-5.11; P = .019). SI was significantly longer in GC that developed at L10AE than at S10AE. In addition, GC with SMD invasion was more frequently detected in L10AE than in S10AE. Our data indicated that SI should not be groundlessly extended in patients at L10AE.