Tumor-Infiltrating Lymphocytes in Breast Cancer. Association with Clinical and Pathological Parameters

In patients with primary resectable breast cancer, a positive correlation between the age and the count of CD16+ lymphocytes and a negative correlation of this parameter with the number of regulatory CD4+CD25+CD127— cells and proliferative activity of Ki-67 tumor cells were revealed. Higher level of Ki-67 was associated with reduced number of effector lymphocytes (CD8+ and CD16+) and elevated content of regulatory CD8+CD11b—CD28— T cells. The absence of expression of estrogen receptors was associated with reduced cytotoxic potential of CD8+ T cell in comparison with ER+ breast cancer. The percentage of CD8+ lymphocytes (CD3+CD8+ and CD8+CD11b+CD28+) among lymphocytes infiltrating the tumor was higher in PR+ breast cancer than in PR— tumors. With increasing the tumor load, the number of lymphocytes expressing CD16 marker and their cytotoxic potential decreased.