The relationship between E-cadherin expression, clinical stage and tumour differentiation in oral squamous cell carcinoma.

OBJECTIVES

To evaluate the expression of E-cadherin, a calcium-dependent cell adhesion molecule, in a retrospective analysis of paraffin embedded tissue specimens of oral squamous cell carcinoma and relationship with the clinical TNM stage and histochemical differentiation.

DESIGN

Paraffin embedded tissue sections of normal oral mucosa (n = 6), oral squamous cell carcinoma (SCC, n = 18) and metastatic lymph nodes (n = 2) were immunostained by a three-stage streptoavidin-biotin immunoperoxidase method using monoclonal antibody. The TNM staging and histochemical grading were done according to the standard criteria.

RESULTS

Normal oral epithelium showed a strongly positive pericellular distribution of E-cadherin in basal, parabasal and spinous layers and no staining was observed in the parakeratinized and cornified layers. In well differentiated SCCs, the centrally located cells in tumour islands showed no staining, but peripheral basally located tumour cells showed positive staining. Poorly differentiated SCCs were devoid of staining. In moderately differentiated SCCs, the staining pattern was found to be one of the following three types: (1) a pattern similar to that of well differentiated SCC; (2) central cells of tumour aggregates were reactive but peripheral cells showed weak to negative reaction; and (3) all cells showed a negative reaction, resembling the poorly differentiated SCC. Fischer exact test showed a statistically significant correlation with loss of E-cadherin and grades of tumour differentiation as well as an advancing T and N stage.

CONCLUSION

The loss of E-cadherin may correlate with advancing T and N stages of the tumour and a poor tumour cell differentiation in oral squamous cell carcinomas.