E-cadherin expression as a differentiation marker in gastric cancer.

E-cadherin is a cell-cell adhesion molecule involved in tumor progression and metastasis. We evaluated the E-cadherin expression pattern in gastric cancer and investigated its relationship to histopathological features. The expression of E-cadherin was evaluated in 83 formalin-fixed, paraffin-embedded specimens of gastric cancer by immunohistochemistry. In benign gastric mucosa, E-cadherin was expressed uniformly at the cell membrane. Abnormal E-cadherin expression with loss of membranous localization was found in 55 (56%) cancer specimens. Aberrant E-cadherin expression was found more often in diffuse (96%) and mixed type tumors (91%) than in intestinal type tumors (47%) (p=0.0001). A significantly higher proportion of signet-ring (84%) and undifferentiated tumors (87%) showed abnormal E-cadherin expression compared with adenocarcinomas with glandular morphology (57%) (p=0.01). There was a significant correlation between abnormal E-cadherin expression and degree of differentiation (p=0.0001), local tumor extent (p=0.002), and the presence of lymph node metastases (p=0.04). Loss of normal E-cadherin expression may serve as a differentiation marker in gastric cancer.