Evaluation of density of tumor-associated macrophages using CD163 in histological grades of oral squamous cell carcinoma, an immunohistochemical study

BACKGROUND: Macrophages account for 30%–50% of the total inflammatory cell population of ''tumor microenvironment'' that plays an important role in cancer metastasis. M2 macrophages are designated as tumor-associated macrophages (TAMs). They are known to orchestrate all the stages of tumor progression. CD163 is TAMs–M2-specific marker. AIMS: The aim of the study was to evaluate the role of TAMs using CD163 in different histological grades of oral squamous cell carcinoma (OSCC). SETTING AND DESIGN: Expression of CD 163 was investigated in 30 histopthologically diagnosed cases of OSCC. MATERIALS AND METHODS: Two sections of 4-μ thickness were stained with hematoxylin and eosin, CD163 (Cell Marque, USA). The expression of TAMs with CD163-positive cells was done by counting the number of macrophages in three high-power fields (×400), and the mean number of macrophages per HPF was evaluated. STATISTICAL ANALYSIS: The statistical analysis was performed using Statistical Software SPSS version 20.0. RESULTS: CD163 TAMs score increasing in higher tumor, node, metastasis stages with significant positive correlation. CONCLUSION: With higher histological grades, CD163 TAMs score increased. Thus, TAMs may be considered as an independent factor for determining the progression of the tumor. The immunotherapeutic approaches to control M2 TAM numbers could protect against progression to malignancy.