IMMUNOHISTOCHEMICAL CHARACTERIZATION OF E48 AND CD44-V6 EXPRESSION INHEAD AND NECK CARCINOMAS

Background-The purpose was to investigate the expression of two cell s urface antigens, E48 and CD44-v6, as markers to characterize the head and neck (HN) squamous cell carcinomas (SCC), The study is a contribut ion to the development of immunostimulating postoperative therapy, Mat erial and Methods-Tumor tissue samples from 60 patients with operable HNSCC were immunohistochemically investigated using the APAAP (alkalin e phosphatase anti-alkaline phosphatase) method with the two monoclona l antibodies (MoAb) E48 (CENTOCOR B.V.,, Leiden/Netherlands) and CD44- v6 (clone VFF-18, Bender, Austria), All tumor specimens came from pati ents who were surgically treated without previous radio-and chemothera py, We determined the percentage and intensities of staining in the ca rcinoma cells, The results were correlated with histopathological tumo r differentiation and UICC classification, Results-All HNSCC studied e xpressed the two surface antigens, However, the portion of non-reactin g tumor regions increased with decreasing differentiation. The percent ages of E48 and CD44-v6 antigen expression were different in SCC cells , and different staining intensities were found, The downregulation of expression of these two antigens with decreasing tumor differentiatio n seems to characterize the phenotype of HNSCC. Conclusions-Both antig ens E48 and CD44-v6 are strongly expressed in tumors with grade 1 HNSC C and also partly in G2-tumors, particularly CD44-v6. We therefore sug gest that patients with G1- or G2-tumors are candidates for a planned postoperative immunostimulation strategy with active or passive vaccin ation.