Additional surgery for non-curative resection after endoscopic submucosal dissection for gastric cancer: a retrospective analysis of 200 cases.

Abstract

Endoscopic submucosal dissection is recommended for early gastric cancer with a low risk of lymph node metastasis. When the pathological findings do not meet the curative criteria; then, an additional gastrectomy with lymph node dissection is recommended. However, most cases have neither lymph node metastasis nor a local residual tumor during an additional surgery. This was a single-institutional retrospective cohort study, analyzing 200 patients who underwent an additional gastrectomy after non-curative endoscopic submucosal dissection from January 2005 to October 2015. We reviewed the patients' clinicopathological data and evaluated the predictors for the presence of a residual tumor. Histopathology revealed lymph node metastasis in 15 patients (7.5%) and a local residual tumor in 23 (11.5%). A multivariable analysis revealed macroscopic findings (flat/elevated type) (p=0.011, odds ratio=4.63), lymphatic invasion (p<0.0001, odds ratio=14.2), and vascular invasion (p=0.04, odds ratio=4.00) to be predictors for lymph node metastasis. A positive vertical margin (p=0.0027, odds ratio=3.26) and horizontal margin (p=0.0008, odds ratio=5.74) were predictors for a local residual tumor. All cases with lymph node metastasis had lymphovascular invasion with at least one other non-curative factor. The risk of a residual tumor can, therefore, be estimated based on the histopathology of endoscopic submucosal dissection samples. Lymphovascular invasion appears to be a pivotal predictor of lymph node metastasis.