IDENTIFICATION OF SIALYL-LEWIS-X IN SQUAMOUS-CELL CARCINOMA OF THE HEAD AND NECK

Background. Sialyl Lewis-x (sLx) is a cellular adhesion molecule (CAM) that has been implicated in the inflammatory reaction and cancer meta stasis. The sLx is the carbohydrate ligand of endothelial-selectin (E- selectin), an inducible vascular endothelial CAM. The role of sLx has been investigated in several cancers, and its presence has been correl ated with advanced disease stage, decreased disease-free survival, and greater metastatic potential. A recent study has found that cultured head and neck (HN) squamous cell carcinoma (SCC) cell lines express sL x and that binding of these cells to cytokine activated endothelium co rrelates with the endothelial expression of E-selectin. The purpose of this study was to identify six in the tumors of patients with HNSCC a nd to see ii the presence of sLx correlated with disease status. Metho ds. We performed immunohistochemical (IHC) staining to detect the sLx antigen using the monoclonal antibody (MAb) KM-93. Eighty-two specimen s of HNSCC that were obtained at the time of resection or biopsy were analyzed for sLx staining patterns and intensities. The clinical outco mes of survival, disease-free interval, and incidence of distant metas tasis were then assessed to determine whether there was a correlation with sLx tumor expression. In addition;we analyzed specimens from meta static HNSCC sites for expression of sLx. Results. The sLx expression was identified in 62% of the primary tumor specimens and 87% of the me tastatic tumor specimens analyzed by IHC. The staining pattern in the HNSCC tumors differed from that seen in normal squamous epithelium but was variable in both intensity and distribution. The sLx expression i n the metastatic sites was higher than in the primary sites in 67% of the specimens (10 of 15). There was no correlation between sLx stainin g and disease status. Conclusions. The results of this study demonstra te that sLx is present in HNSCC and supports the data that show that s Lx may play a role in the metastasis of HNSCC. Future studies are warr anted to evaluate the role of six, E-selectin, and other CAMs in HNSCC . (C) 1998 John Wiley & Sons, Inc.