Deranged expression of the E-cadherin/β-catenin complex and the epidermal growth factor receptor in the clinical evolution and progression of oral squamous cell carcinomas

Background: Deranged expression and function of the E-cadherin/beta-catenin (E-cad/beta-cat) complex and the epidermal growth factor receptor (EGFR) have been implicated in the development and progression of carcinomas. Methods: To estimate the role of these molecules in oral cancer, we investigated 75 primary oral squamous cell carcinomas (OSCCs) with adjacent normal and/or dysplastic mucosa, 30 paired metastases and 12 recurrences by immunohistochemistry. Results: All three molecules were constitutionally expressed in the basal/parabasal layers of tumour adjacent 'normal' epithelium, in contrast to a significant increase of EGFR and heterogeneous expression of E-cad/beta-cat in dysplasia. In OSCCs, overexpression of EGFR correlated significantly with lower tumour grade and poor prognosis, loss of E-cad was a significant marker for shortened survival, reduced beta-cat staining was a predictive marker for lymph node metastasis. Conclusions: There is a perturbance in intercellular adhesion molecules and EGFR expression/function in oral cancer with major clinical impact. E-cad and beta-cat seem to inhibit EGFR to enhance the progression of OSCCs.