Risk factors predictive of lymph node metastasis in depressed early gastric cancer.

Background: This study was conducted to identify risk factors predictive of regional lymph node metastasis in depressed early gastric cancer and further to establish an objective criterion useful to indicate additional surgical treatment in cases in which submucosal tumor extension becomes evident by endoscopic mucosal resection (EMR).

Methods: Data from 276 patients surgically treated for depressed early gastric cancer were collected, and the relationship between the patient and tumor characteristics, and the lymph node metastasis was retrospectively evaluated by multivariate analysis.

Results: In the multivariate logistic regression model, female sex, a larger tumor size (20 mm or more), submucosal invasion, and presence of lymphatic vessel involvement were found to be independent risk factors for lymph node metastasis. Among 145 patients with submucosally invasive carcinoma, no lymph node metastasis was observed in patients who showed none of the other three risk factors, whereas 14.3% and 23.3% of patients with one and two of these factors had lymph node metastasis, respectively. The lymph node metastasis rate was calculated to be 86.7% in patients who had all three factors.

Conclusions: Submucosal invasion, female sex, tumor size of 20 mm or more, and lymphatic vessel involvement were significantly and independently related to the presence of lymph node metastasis in depressed early gastric cancer. The positive number of the latter three risk factors is a simple criterion to indicate additional surgical treatment in cases with submucosal invasion revealed first by EMR.