Lymph node status in patients with submucosal gastric cancer

Background: The aim of this study was to clarify the lymph node status in patients with submucosal gastric cancer. Methods: Between April 1994 and December 1999, 615 patients with histologically proven submucosal gastric cancer who underwent curative resection were included in this study. The results of the surgery and predictive factors for lymph node metastasis were evaluated by univariate and multivariate analyses. The accuracy of the predictive factors was assessed in a second population of a further 186 patients. Results: Lymph node metastasis was observed in 119 patients (19.3%). Multivariate analysis showed that pathologic tumor diameter ( >= 20 mm) and lymphatic invasion were independent predictive factors for lymph node metastasis. The incidence of lymph node metastasis without these 2 predictive factors was 1.8% (2 of 113), and it was 51.2% (85 of 166) with the 2 predictive factors, 9.5% (14 of 148) in tumors < 20 mm in diameter, and 5.3% (22 of 414) in tumors without lymphatic invasion. Among patients with a tumor < 20 mm in diameter, the incidence of lymph node metastasis was significantly reduced in those with a differentiated tumor: 4.2% (4 of 95). These results were almost identical to those observed in the second population. Conclusions: Lymph node status can be accurately predicted on the basis of pathologic tumor diameter < 20 mm, lymphatic invasion (absence), and histological type (differentiated) in patients with submucosal gastric cancer. Less extensive surgery for these patients might be reconsidered after confirmation of the reproducibility of the results of this study by an appropriately designed prospective clinical trial.