Aims: Reduction or loss of E-cadherin expression was examined in early gastric carcinomas and precursor lesions with the following aims: (1) to assess overall E-cadherin expression in various stages of gastric carcinogenesis; (2) to correlate E-cadherin expression with the Lauren type, the grade of differentiation and the type of growth pattern of the tumours; and (3) to correlate E-cadherin expression with lymph node metastasis and overall prognosis.
Methods and results: Forty-five paraffin-embedded gastrectomy specimens from early carcinomas were examined for the presence of various precursor lesions. The Lauren type, the grade of differentiation and the type of growth pattern were reassessed for all early carcinomas. E-cadherin expression was examined using antibody HECD-1. Whereas E-cadherin was strongly and evenly expressed in the gastric foveolar epithelium, intestinal metaplasia and early gastric carcinomas showed a lower expression. A significant difference in E-cadherin expression was found between the Lauren types (P < 0.0001). Moreover, an inverse correlation was found between E-cadherin expression and histological grade (P < 0.0001). Neither a difference in E-cadherin expression between the various growth types nor an association with lymph node metastasis and overall prognosis was found.
Conclusions: The Lauren types differ in E-cadherin expression, although reduced E-cadherin expression in all probability rather reflects poor differentiation than a diffuse growth pattern 'genotype'. Moreover, E-cadherin expression does not underlie the difference in biological behaviour of early carcinomas with different types of growth pattern. Finally, E-cadherin expression is not associated with lymph node status and 5-year survival rate, at least not in early gastric carcinomas.