Loss of epithelial cell adhesion molecule (EpCAM) in infiltrative basal cell carcinoma

Basal cell carcinoma (BCC) is the most common type of skin cancer and expresses high protein levels of the epithelial cell adhesion molecule (EpCAM, syn. CD326). Though BCCs only rarely metastasize, infiltrative and destructive growth do occur. EpCAM has been studied extensively in the context of adhesion and carcinogenesis but results of studies relating EpCAM expression to invasive potential or patient prognosis have been inconsistent. In an attempt to link EpCAM expression with infiltrative potential, we retrospectively stained paraffin embedded tissue samples of nodular and infiltrative BCCs. A total of 96 samples comprising 48 nodular and 48 infiltrative BCC cases were immuhistochemically stained with anti-EpCAM clone BerEP4. Loss of EpCAM expression along the tumor invasive front was detected in 6 of 48 (12.5%) of the nodular BCC as compared to 29 of 48 (60.4%) of the infiltrative BCC cases (P < 0.0001). These results exemplify the important role of EpCAM for cell adhesion. BCC infiltration seems to be promoted by down-regulation of EpCAM along the tumor invasion front.