Possibilities of investigating intratumoral lymphocyte subpopulations by flow cytometry of tumor core biopsy specimens in patients with breast cancer

Study of tumor-infiltrating lymphocyte subpopulations was performed in 19 patients with breast cancer (core biopsy material). Two probes were used in multiparameter flow cytometry: CD4/CD25/CD3/CD45 and CD8/CD56/CD3/CD45. Mean percentage of different cell types within lymphocytes (CD45++ SSCLow) was as follows: CD3 – 88.2%, CD4 – 45.1%, CD8 – 40.4%, NK (CD3–CD56+) – 1.6%, CD4+CD25+ – 4.1 %. Ratio CD8/CD4 was less than 1 in 53 % of cases. In cases of prominent and moderate CD45 infiltration percentage of CD8+ lymphocytes was significantly higher than in cases with low infiltration, p = 0.007.