Macrophages polarization and density of tumor-associated dendritic cells correlated with depth of invasion in gastric adenocarcinoma

Introduction: Tumor-associated macrophages (TAM) are the most common inflammatory cells in the tumor microenvironment (TM). As a response to microenvironmental signals, they polarize into tumor resisting M1 or promoting M2 macrophages. TAM and tumor-associated dendritic cells (TADC) can either promote tumor growth and tissue invasiveness or have anti-tumor activity. The aim of the study was the examination of prognostic value in the individual cell population in TM and their correlation with clinicopathological parameters of gastric cancer. Materials and Methods: The study analyzed 60 samples of gastric cancer, known status of regional lymph nodes and without dissemination at the time of diagnosis. The control group was normal gastric tissue samples. Traditional parameters of biological aggressiveness, tumor size, histological grade, and lymphovascular invasion, are determined after standard hematoxylin-eosin staining. TAM and TADS have been evaluated using the immunohistochemical method with CD68 (TAM), TNFa (TAM-M1), CD163 (TAM-M2), and S100 (TADC) antibodies. Expression evaluation of the tissue antigen was carried out by semiquantitative methods. Results: There were statistically significant differences of TAM density (P 0.05). Conclusion: TAMs and TADC have shown potential as biomarkers for evaluating the gastric cancer staging and progression. They showed promising prediction in depth of invasion, histological grade of tumor and tumor size. Keywords: gastric cancer, tumor microenvironment, TAM, TAM-M1/M2, TADC