The prognostic influence of tumor infiltrating M1 and M2 phenotype macrophages in resected non-small cell lung cancer

Abstract

Introduction. Non-small cell lung cancer (NSCLC) remains the most common cause of cancer related death worldwide. Tumor infiltrating macrophages are believed to play essential role in the immune response to cancer cells. Study aim was to evaluate the tumor infiltrating macrophages (M1 and M2) and to analyze their relations to patients9 survival. Methods. We recruited 80 patients with primary NSCLC (stages I-III) with median age 66 years (ranges 45-77). Paraffin-embedded sections of surgically resected tumor were analyzed. Immunohistochemical double staining of CD68/iNOS (markers for M1 macrophages) and CD68/CD163 (markers for M2 macrophages) was performed and evaluated in blinded manner. Quantitative evaluation of these cells was done in 10 most representative high-power fields (HPFs ×400 magnification) per tissue section. Results . Predominant infiltration of M1 and M2 macrophages was observed in tumor stroma compared to tumor islets (P Conclusions. Our study demonstrated that tumor islets infiltrating M1 macrophages are associated with improved NSCLC patients9 survival, while increased total number of tumor infiltrating M2 macrophages is associated with poor survival.