Epithelial and Stromal Expression of Syndecan-1 (CD138) in Cutaneous Basal Cell Carcinoma

Syndecan-1 (Sdc-1) is an important regulator of cell–cell and cell–extracellular matrix interactions. It is significantly involved in the carcinogenesis and tumor progression in many human malignancies. We immunohistochemically investigated Sdc-1 expression in cutaneous basal cell carcinoma (BCC) in order to clarify, whether there is difference in the expression pattern related to tumor growth characteristics. The study group consisted of 46 BCCs cathegorized into non-infiltrative and infiltrative growth variants. Specific antibody against Sdc-1 (clone MI15) was used for staining. There were 4 cases (8.7%) with preserved and 40 cases (87%) with reduced epithelial Sdc-1 expression, of which 20 cases were slightly and 20 cases severely reduced. Two BCCs (4.3%) showed a completely negative staining. Further, there were 13 BCCs (28.3%) with focal immunoreactivity in adjacent peritumorous stroma, a ll of which manifested infiltrative growth feature. We did not confirm a significant association between the expression of Sdc-1 in tumor tissue and both, non-infiltrative and infiltrative BCC variants. However, there was a significant association between the stromal immunoreactivity for Sdc-1 and infiltrative growth pattern of tumor. Sdc-1 expression was commonly reduced in neoplastic epithelial BCC tissue regardless of histologic subtypes. It did not clearly appear to be associated with tumor invasiveness. However, immunoreactivity in adjacent peritumorous stroma was found only in BCCs with infiltrative growth pattern, most of which showed apparent loss of Sdc-1 in epithelial cancer tissue. This immunostaining pattern could be a sign of more aggressive biologic behaviour of BCC.