P2 Correlation of macrophage polarization and Gal-3 expressing cells in oral squamous cell carcinomas with the occurrence of lymph node metastases

Abstract

Background TNM classification and grading describe tumorbiological parameters of the oral squamous cell carcinoma (oscc) only incompletely. In solid malignancies the influence of immunological parameters on invasiveness, metastatic potential and prognosis could be shown. There are no studies correlating macrophage polarization and Galectin-3 (Gal-3) expression in oscc specimens yet. The phylogenetically highly conserved glycoprotein Gal-3 is involved in the regulation of macrophage polarization (M1/M2). The aim of this study was to correlate macrophage polarization and Gal-3 expression of primary oscc with histopathological parameters (N-, L-, V-, Pn-status, grading). Material and Methods Oscc tumor resection specimens ( n = 30) were investigated by immunohistochemistry. Automated staining with an LSAB-kit was used to detect CD68, CD11c, CD163, MRC1 and Gal-3 positive cells. Complete digitalization of all samples using “whole slide imaging” and quantitatively assessment of the number of stained cells per area was performed. The expression of markers in the epithelial tumor compartment and in the stroma was considered separately. The study was funded by the ELAN-Fonds der FAU Erlangen-Nurnberg (ELAN 12.01.02.1). Approval of ethics committee: (EK No. 45_12 Bc.). Results In tumors with primary lymph node metastasis (N+) compared to N0 tumors, a significantly ( p p p Conclusion These results show an increased macrophage infiltration as well as an increased M2-polarization in primary lymphogenic metastatic oscc. In particular, the macrophages that migrated into the epithelial tumor fraction seem to be of special biological importance. Besides the TNM classification, immunological parameters could be used for the clinical and prognostic evaluation of oral squamous cell carcinomas. The results support the concept of a tumor-derived peripheral tolerance, because the immunomodulatory Gal-3 shows an increased expression in primary metastatic (N+) tumors.