Pathological factors related to lymph node metastasis of submucosally invasive gastric cancer: criteria for additional gastrectomy after endoscopic resection.

Background: There are currently no universally accepted indications and criteria for additional gastrectomy after endoscopic resection of submucosally invasive cancer. The purpose of the present study was to establish accurate indications and criteria for such additional gastrectomy on the basis of lymph node metastasis risk.

Methods: We investigated 130 submucosally invasive gastric cancers and analyzed the pathological risk factors for lymph node metastasis. The tumors were evaluated for pathological factors in the area of invasion, and factors were compared between the cases with lymph node metastasis and those without.

Results: Univariate logistic regression analysis showed that tumor minor axis length, depth of invasion, histological classification of the area of submucosal invasion, absence of lymphoid infiltration, ulceration or scar in the lesion, and lymphatic and venous invasion are statistically significant risk factors for lymph node metastasis. Multivariate logistic regression analysis showed that the absence of lymphoid infiltration and the presence of lymphatic invasion are statistically significant as risk factors for lymph node metastasis.

Conclusions: We present a scoring system on the basis of the pathological criteria tested in this study. Our findings enable more accurate identification of patients who should undergo additional gastrectomy after endoscopic resection.