A scoring system for patients with a tumor-positive lateral resection margin after endoscopic resection of early gastric cancer

The aim of this study was to identify the risk factors for residual/recurrent tumors in patients with a tumor-positive lateral resection margin (LRM+) after endoscopic resection of early gastric cancer (EGC) and to establish the criteria for performing additional treatment. A retrospective analysis was performed on consecutive patients who underwent endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) of EGC. Clinicopathological characteristics and risk factors for residual/recurrent tumor in LRM+ patients were analyzed. Eighty-two patients (84 lesions) with LRM+ after EMR (n = 45) or ESD (n = 39) were enrolled. Forty patients underwent additional gastrectomy or ESD, and 44 were closely observed. The residual/recurrent tumor rate was 34.5 % (29 of 84 lesions). Univariate analysis found that the residual/recurrent tumor was associated with the endoscopic resection type (EMR), undifferentiated histology, number of involved directions, rate of lateral resection margin involvement and the total length (mm) of the lateral resection margin involved by the tumor. In multivariate logistic regression analysis, undifferentiated histology and rate (%) were independent risk factors (odds ratio [OR] 5.28, 95 % confidence interval [CI] 1.13-24.72, p = 0.035 and OR 1.08, 95 % CI 1.03-1.14, p = 0.004, respectively). Clinicopathological factors that were identified from the univariate and multivariate analyses were scored in order to predict residual/recurrent tumors. We suggest a scoring system for additional treatment in patients with LRM+ after endoscopic resection of EGC based on the development of residual/recurrent tumors. This scoring system enables a more detailed selection of cases and may be useful in determining further treatment.