Factors Associated with Metachronous Gastric Cancer Development after Endoscopic Submucosal Dissection for Early Gastric Cancer

Goals: To clarify the factors associated with metachronous gastric cancer development after endoscopic submucosal dissection (ESD) for early gastric cancer. Background: Patients who undergo ESD for early gastric cancer have an appreciable risk of developing metachronous gastric cancer. However, there have been few reports on the association between life style and the development of such cancer. Study: Patients with early gastric cancer who underwent ESD at our institution between 2003 and 2012 were enrolled. Metachronous gastric cancer was defined as secondary gastric cancer detected >1 year after initial ESD. Factors, including age, gender, body mass index, eradication of Helicobacter pylori, cigarette smoking, drinking, and continuous use of a proton pump inhibitor, associated with metachronous gastric cancer development were evaluated by Cox proportional hazard regression analysis. Results: A total of 539 patients with a mean 53.6-month follow-up period were analyzed. The 5-year cumulative incidence of secondary gastric cancer was 13.0%. Multivariate analysis exhibited that age of 60 years and above [hazard ratio (95% confidence interval)=4.05 (1.23-13.4)] and cigarette smoking [2.12 (1.19-3.78)] were independent risk factors for metachronous gastric cancer development. Furthermore, ≥20 pack-years of smoking [1.51 (1.03-2.24)] was a significant risk factor with a dose-response relationship (P for trend=0.042). There was no significant association between Helicobacter pylori eradication and metachronous gastric cancer development. Conclusions: This is the first study to demonstrate the detailed association between cigarette smoking and metachronous gastric cancer development.