Effect of Helicobacter pylori eradication on metachronous recurrence after endoscopic resection of gastric neoplasm.

Abstract

Although many epidemiologic studies have shown that Helicobacter pylori (H. pylori) eradication has prophylactic effects on gastric cancer, their results are less clear in high-risk populations. We conducted this study to examine whether H. pylori eradication would affect the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer. We retrospectively analyzed 2,089 adults who underwent endoscopic resection of gastric low-grade neoplasia, high-grade neoplasia, or differentiated invasive neoplasia from 2004 to 2008 at Asan Medical Center. Of these, a total of 1,007 patients with early gastric cancer were enrolled in this study. We evaluated the demographic data, the pathology, and the incidence of metachronous recurrence by dividing them into three groups: those without active H. pylori infection (Hp negative group, n=340), those who successfully underwent H. pylori eradication (eradicated group, n=485), and those who failed or did not undergo H. pylori eradication (noneradicated group, n=182). Metachronous recurrence was diagnosed in 75 patients, including 17 in the Hp, 34 in the eradicated, and 24 in the noneradicated groups. Median time to metachronous recurrence was 18 months (range, 7-75 months). The incidence of metachronous gastric cancer was 10.9 cases per 1,000 person-years in the Hp negative group, 14.7 cases per 1,000 person-years in the eradicated group, and 29.7 cases per 1,000 person-years in the noneradicated group. The hazard ratios in the noneradicated group compared with the Hp negative and eradicated groups were 2.5 (P<0.01) and 1.9 (P=0.02), respectively. H. pylori eradication reduced metachronous recurrence of gastric neoplasm, which was also shown in the secondary analysis of 1,487 patients with low-grade neoplasia and early gastric cancer. Successful H. pylori eradication may reduce the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.