Identification of clinicopathological factors predicting lymph node metastasis in differentiated submucosal gastric cancer: Impact on surgical strategy.

The aim of this study was to identify the clinicopathological factors predictive of lymph node metastasis (LNM) in differentiated submucosal gastric cancer (SGC), and to establish a simple criterion which may be useful in selecting the optimal treatment for cases with SGC. A total of 70 patients with differentiated and surgically treated SGC were retrospectively examined, and the association between the clinicopathological factors and the presence of LNM was retrospectively analyzed by univariate and multivariate logistic regression analyses. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated. In the univariate analysis, tumor size, lymphatic vessel involvement and the presence of intermingled components of undifferentiated cancer cells were significantly associated with a higher rate of LNM (all P<0.05). In the multivariate analysis, lymphatic vessel involvement (OR=392.269; 95% CI 1.380-1115.032; P=0.038) and presence of intermingled components of undifferentiated cancer cells (OR=98.515; 95% CI 2.687-3612.400; P=0.012) were found to be independent pathological risk factors for LNM. LNM was observed in 75.0% (3/4) of patients with the two risk factors, but in none of the 45 patients without the two risk factors. Lymphatic vessel involvement and presence of intermingled components of undifferentiated cancer cells are independently associated with the presence of LNM in differentiated SGC. Thus, these two risk factors may be used to establish a simple criterion to guide further surgical procedures in cases with SGC revealed after endoscopic mucosal resection (EMR).