Abstract
Aim : To establish the appropriate indication of endoscopic treatment for submucosal invasive gastric carcinoma, we reevaluated the risk factors of lymph node (LN) metastasis in 166 cases of differentiated type submucosal invasive gastric carcinoma that had been resected surgically. Results : 29 (17%) of 166 lesions showed histologic heterogeneity. When the submucosal invasive part showed an undifferentiated type, LN metastasis was detected in 6 (21%) of 29 cases. When the submucosal invasive part showed a differentiated type, however, LN metastasis was detected in 18 (13%) of 137 cases. The incidence of LN metastasis of undiffer-entiated type at the submucosal invasive part was higher than that of differentiated type. Well differentiated adenocarcinoma (tub 1) lesion showed no LN metastasis in cases with less than 700pm submucosal invasion. However, moderately differentiated adenocarcinoma lesions (tub2) showed a LN metastasis even in case with minimal submucosal invasion of 300pm. In the result of the multivariate analysis, lymphatic invasion, infiltrative growth pattern (INF)γ and papillary adenocarcinoma (pap) were significant risk factors for LN metastasis. Conclusions : The differentiated type submucosal invasive gastric carcinomas of pap and tub2 at the deepest part showed a higher incidence of LN metastasis. Pap and tub2 lesions should not be included for indications of curative endoscopic mucosal resection (EMR). On the other hand, tubl lesion of INF α without lymphatic invasion showed no LN metastasis. These results indicate that minimal submucosal invasive gastric carcinoma with tubl at the deepest invasive portion and no lymphatic invasion, which shows no other risk factors, can be considered as the appropriate indication for curative EMR.
