Normal and dysplastic mammary glands express immunocompetent S-100 proteinpositive dendritic cells (DCs), which are located in a regular pattern, in the suprabasal cell layerof the ducts and alveolar nodules. The epithelial cells, however, are S-100 protein negative. Since somebreast cancers also express the S-100 protein, our aim was to check the diagnostic and prognostic valueof the S-100 protein distribution combined with the tumor grade and expression of synaptophysin (Syn),chromogranin A (Chg A), c-erbB-2 oncoprotein and p53 protein in infiltrating and metastatic breast tumors.Applying immunohistochemical methods, we show in paraffin- or frozen breast tissue sections that in somecases of the infiltrating breast carcinomas, S-100 protein positive cells do not appear, whereas in othercases, either S-100 protein positive DCs are closely associated with cancer cells, or the cancer cellsthemselves stain positive to S-100 protein. However, we found no correlation between the S-100 proteinexpression and other investigated parameters.

Keywords: Tumor Suppressor Protein p53