Gastric Cancer with Submucosal Invasion after Successful Helicobacter pylori Eradication: A Propensity Score-Matched Analysis of Patients with Annual Patient Endoscopic Survey.

BACKGROUND AND AIM: The incidence of gastric cancer occurring after successful Helicobacter pylori eradication has been increasing. We aimed to clarify the influence of eradication therapy on the ability to diagnose early gastric cancer after successful H. pylori eradication in patients who underwent annual endoscopic screening.

METHODS: A total of 220 patients (179 men; mean age 71.0 years) had differentiated-type early gastric cancer that was discovered through annual endoscopic screening. Patients were categorized into 2 groups: the H. pylori-eradicated group (n = 81) and the non-eradicated control group (n = 139). After matching patients by propensity scores, we retrospectively analyzed the clinicopathological characteristics of 162 patients (81 patients in each group). Furthermore, we compared the characteristics of gastric cancer with submucosal invasion between the 2 groups.

RESULTS: The prevalence of early gastric cancer with submucosal invasion was significantly higher in the eradicated group than in the control group, both before propensity score matching (16.0 vs. 7.2%, respectively; p = 0.038) and after propensity score matching of 81 pairs (16.0 vs. 4.9%, respectively; p = 0.021). In the comparative analysis of gastric cancer with submucosal invasion, there was no difference between the 2 groups with respect to factors influencing the ability to diagnose its presence endoscopically.

CONCLUSION: H. pylori eradication therapy increased the prevalence of differentiated-type gastric cancer with submucosal invasion despite patients' completion of annual endoscopic screening after eradication.