Significance of dysadherin and E-cadherin expression in differentiated-type gastric carcinoma with submucosal invasion

Dysadherin is a cancer-associated cell membrane glycoprotein that down-regulates E-cadherin and plays important roles in tumor progression and metastasis. Differentiated-type gastric carcinoma can be classified into 2 histologic subtypes according to the presence of poorly differentiated components: a mixed type (differentiated carcinoma with poorly differentiated components) and a pure type (purely differentiated-type adenocarcinoma). We studied the clinicopathologic features of 318 cases of differentiated-type gastric carcinoma with submucosal invasion and evaluated the immunohistochemical expression of dysadherin and E-cadherin. We also evaluated 46 cases of metastatic lymph nodes. Tumors with combined dysadherin-positive (≥50%) expression and E-cadherin-negative (<50%) expression had significantly higher proportions of the moderately differentiated type, deeper submucosal invasion, positivity of lymphatic permeation, and positivity of lymph node metastasis than tumors with other combinations of dysadherin and E-cadherin expression (P = .0009, P = .0015, P = .0273, and P = .0187, respectively). Moreover, the frequency of dysadherin-positive (≥50%) expression was higher in the mixed type (60.3%) than in the pure type (12.4%) (P < .0001), whereas the frequency of E-cadherin-negative (<50%) expression was higher in the mixed type (84.5%) than in the pure type (50.5%) (P < .0001). The frequency of dysadherin expression in the metastatic lymph nodes (80.4%) was significantly higher than that in the primary tumors (45.7%) (P = .001). Dysadherin-positive (≥50%) expression and E-cadherin-negative (<50%) expression may be correlated with the mixed type. Combined dysadherin-positive (≥50%) expression and E-cadherin-negative (<50%) expression may be valuable information for predicting aggressive tumor behavior.