Background & Objective: Tumor-infiltrating lymphocytes (TILs) develop as recognition and defense against malignant cells by the host immune system. T cells are the most tumor infiltrating immune cells. There are controversial data about intratumor T cells and many have proposed diverse mechanisms for dysfunction of TILs. The aim of this study is analyzing Tumor Infiltrating T lymphocytes in patients with breast cancer by immunophenotyping.
Methods: Sixteen women suffering from breast cancer were examined; thirteen of them were confirmed histologically to be invasive ductal carcinoma (IDC). Tissue samples from patients and matched control group were processed for analysis by flow cytometry.
Results: Results indicated that human breast cancer contain variable numbers of TILs. No significant changes in the percent of intratumor CD45+, CD3+ and CD3+/CD45+ cells were observed between studied group. Also there were no significant differences between cancer patients (group 1 and 2) and control group in the case of infiltration and activation status of T cells subpopulations. CD4+ cells in IDC patients and CD8+ cells in patients with other tumors (ILC+AMC) were the most infiltrated TILs. Intratumor TCD8+ cells expressed HLA-DR markers significantly more than CD25 as activation marker. In this investigation we could not find any correlation between TIL and both size and clinical stages of tumor.
Conclusion: An immune infiltrate is an invariable finding in breast cancers, with considering the activation marker expression, TIL may be activated, albeit partially. Understanding the insensitive and/or suppressive nature of cancer cells to the immune system may provide important insights into tumor escape mechanisms as well as the development of anti-cancer strategies
