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(+)CD11bCD28 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.