Endoscopic Resection is Infeasible for Early Gastric Cancers with Undifferentiated Components.

Background/aims: Aim of this study is to find subgroup of early gastric cancer with lymph node metastasis for which successive further surgical operation is needed after endoscopic resection.

Methodology: A total of 559 lesions of early gastric cancer, which had undergone curative gastrectomy, were enrolled in this study. We retrospectively investigated 10 clinicopathological factors predictive of lymph node metastasis by univariate and multivariate analysis. We showed the frequency of lymph node metastasis of subgroups in combination of independent factors selected by multivariate analysis.

Results: Lymph node metastases were detected in 57 lesions (10.2%). Univariate analysis revealed that lesion size > 30 mm, undifferentiated components, sm massive invasion, lymphatic invasion and venous invasion were factors significantly correlated with lymph node metastasis. By multivariate analysis, risk factors for lymph node metastasis were lesion size > 30 mm, undifferentiated components, sm massive invasion, and lymphatic invasion, with odds ratios of 2.17, 2.30, 5.88 and 8.24, respectively. In lesions with undifferentiated components, LNM were found in all subgroups.

Conclusions: When we treat early gastric cancers contained undifferentiated components, even if they are predominantly differentiated-type intramucosal lesions, an additional surgical procedure should be considered or careful follow-up is required.