Expression of Ep-CAM, but not of E48, associates with nodal involvement in advanced squamous cell carcinomas of the larynx

Aims To evaluate epithelial cell adhesion molecule (Ep-CAM) and E48 expression, and their relationship with histological differentiation and nodal metastasis, in laryngeal squamous cell carcinomas (SCC). Methods and results The expression of Ep-CAM and E48 was investigated using immunohistochemistry in a series of 66 SCC (stages 3 and 4) and their adjacent non-neoplastic epithelia. Ep-CAM expression increased with the progression from normal squamous epithelium to SCC. It was detected in 96% of carcinomas and high levels of Ep-CAM expression (50% or more positive cells) were associated with poorer differentiation (P=0.003) and the presence of lymph node metastases (P=0.001). E48 expression was characteristically strong and diffuse in non-neoplastic squamous epithelium, and decreased with progression to SCC. Poorly differentiated (grade 4) tumours had lower proportions of E48-positive cells than well- to moderately- differentiated cases (P<0.001). Conclusions Expression of both Ep-CAM and E48 correlated with cell differentiation, although in inverse fashion. In particular, the association between high levels of Ep-CAM expression and high frequency of nodal metastases suggests that Ep-CAM plays a role in the development of lymph node metastases in SCC of the larynx.