Impact of the timing of Helicobacter pylori eradication on the risk of metachronous lesion development after the treatment of early gastric cancer: a population-based cohort study.

Abstract Background and Aims Helicobacter pylori eradication can reduce the risk of metachronous lesions after the treatment of early gastric cancer. We aimed to analyze the impact of the timing of H pylori eradication on metachronous recurrence. Methods Data of patients who underwent endoscopic resection or partial gastrectomy for early stage gastric cancer and received H pylori eradication therapy were obtained from the Korean National Health Insurance Service database. Patients were classified into 3 groups according to the prescription timings of H pylori eradication: preresection; within 1 year postresection; and >1 year postresection. Results Among 19,767 patients, 7,452 and 12,315 underwent endoscopic resection and surgery, respectively. The 5-year cumulative incidence of metachronous lesions after endoscopic resection was 14.0% in the preresection group, 12.3% in the within 1 year postresection group, and 16.9% in the >1 year postresection group, whereas that after surgery was 1.2% in the preresection group, 1.3% in the within 1 year postresection group, and 2.9% in the >1 year postresection group. The within 1 year postresection group had a lower risk of metachronous lesion development than the >1 year postresection group (hazard ratio [95% confidence interval]: after endoscopic resection, 0.79 [0.65–0.95]; after surgery, 0.39 [0.28–0.53]). The risk of metachronous lesion development did not differ between the preresection and within 1 year postresection groups. Conclusion Prescription of H pylori eradication therapy within 1 year after gastric cancer treatment reduces the risk of metachronous gastric neoplasm development compared with a late prescription of eradication therapy in both patients undergoing endoscopic resection and those undergoing surgery.