Immunolocalization of E-cadherin in human head and neck cancer.

Loss of expression of the cell-cell adhesion molecule E-cadherin has been shown to have a potential role in the dedifferentiation and progression of many human malignancies. We applied immunohistochemical staining for E-cadherin to eight formalin-fixed, paraffin-embedded primary and matched metastatic human head and neck carcinomas. In tumors that contained both well-differentiated and poorly differentiated components, staining was notably reduced in the poorly differentiated cells. Staining was nearly identical or only slightly reduced in metastases compared to primary tumors. As found in previous reports, E-cadherin expression may be involved in the dedifferentiation of these tumors.