Survival Benefit of Additional Surgery After Non-curative Endoscopic Submucosal Dissection for Early Gastric Cancer: A Propensity Score Matching Analysis

Background and Purpose: Previous studies comparing survival outcomes between patients who did and did not undergo additional surgery after non-curative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) were limited in that the baseline characteristics differed significantly between the groups. We aimed to address this limitation and compared survival outcomes between these two groups using propensity score matching analysis. Methods: The study enrolled 1969 consecutive patients who underwent non-curative ESD for EGC between 2000 and 2011 at any of 19 institutions across Japan. Using propensity score matching analysis, patients who underwent additional surgery (n = 1064) were compared with patients who did not (n = 905). Overall survival (OS) and disease-specific survival (DSS) after ESD were compared between both groups. Results: Propensity score matching analysis yielded 553 matched pairs and well-balanced baseline characteristics between the two groups. The 5-year OS rates were 91.0% in the additional surgery group and 75.5% in the no additional surgery group, and the 5-year DSS rates were 99.0 and 96.8%, respectively. OS and DSS in the additional surgery group were significantly higher than in the no additional surgery group (OS, p < 0.001; DSS, p = 0.013). In Cox proportional hazard analysis, additional surgery significantly reduced gastric cancer-related death after non-curative ESD for EGC (hazard ratio 0.33, 95% confidence interval 0.12–0.79, p = 0.012). Conclusions: Our findings suggest that additional surgery reduces mortality after non-curative ESD for EGC. We recommend additional surgery for patients after non-curative ESD for EGC.