Macrophage phenotypes and their expression in non-small cell lung cancer

Abstract

22132 Background: The role played by the innate immune system in determining survival from non-small cell lung cancer (NSCLC) is unclear. There is a survival advantage for patients with NSCLC expressing high numbers of macrophages in their tumour islets. The aim of this study was to investigate the immunological phenotype of islet and stromal macrophages in NSCLC. Methods: We used double-stain immunohistochemistry to identify CD68+ macrophages along with markers of either the non-cytotoxic M2 phenotype (CD163), or the cytotoxic M1 phenotype (HLA-DR,inducible nitric oxide synthase (iNOS), myeloid-related protein 8/14 dimerisation (MRP 8/14) and tumour necrosis factor-alpha (TNFα). This was performed on surgically resected tumours for 20 patients with good survival (median 92.7 months) compared to 20 patients with poor survival (median 7.7 months). Results: CD68+ macrophages were detected in both the tumour stroma and islets in all patients. There were significantly more double-stained CD68+ macrophages for...