Predictive factors for lymph node metastasis in early gastric cancer with submucosal invasion: analysis of a single institutional experience

OBJECTIVE: An accurate assessment of a potential lymph node metastasis is an important issue for the appropriate treatment of early gastric cancer. Minimizing the amount of invasive procedures used in cancer treatment is critical for improving the patient's quality of life. Therefore, this study analyzed the predictive risk factors for a lymph node metastasis in early gastric cancer with a submucosal invasion. METHODS: The data from 1043 patients surgically treated for early gastric cancer with submucosal invasion between 2002 and 2005 were reviewed retrospectively. The patients were divided into 3 layers according to their depth: SM1, SM2, and SM3. The clinicopathological variables predicting a lymph node metastasis were evaluated. RESULTS: A lymph node metastasis was observed in 19.4% of patients. The tumor size, histologic type, Lauren classification, tumor depth, and perineural invasion showed a positive correlation with the rate of lymph node metastasis and N category by univariate analysis. Multivariate analyses revealed the tumor size (>or=2 cm) and lymphatic involvement to be significantly and independently related to lymph node metastasis. The presence of lymphatic involvement was the strongest predictive factor for a lymph node metastasis, being observed in 43.8% of cases in which a lymph node metastasis had been revealed. No lymph node metastasis was observed in the 12 cases with no lymphatic involvement, SM1 invasion, and tumor size <1 cm. CONCLUSIONS: Lymphatic involvement and tumor size are independent risk factors for a lymph node metastasis in early gastric cancer with submucosal invasion. Minimal invasive treatment, such as endoscopic mucosal resection, may be possible in highly selective submucosal cancers with no lymphatic involvement, SM1 invasion, and tumor size <1 cm.