RELATIONSHIP OF LYMPHOCYTE SUBPOPULATIONS IN BREAST CANCER PATIENTS WITH TREATMENT RESULTS

Abstract

Introduction. Breast cancer (BC) is an immunogenic tumor. Immune cells infiltration of tumor tissue can affect the clinical course of the disease. The immunogenicity of breast cancer varies depending on the molecular subtype.The aim of this work was to study the main indicators of systemic and local immunity before patient’s treatment and to determine their relationship with the immediate neoadjuvant chemotherapy results.Materials and methods. Patients with stage II–III BC received standard neoadjuvant chemotherapy in accordance with the molecular subtypes. The percentage of the main effector and regulatory lymphocytes populations of systemic and local immunity was determined by flow cytometry.Results. A decrease in the level of effector CD8 and CD4 lymphocyte populations and an increase in the level suppressor populations in tumor tissue in comparison with peripheral blood indicate an immunosuppressive state of local immunity in BC patients. In tumor tissue, a high level of CD8+ PD-1+ and CD4+ PD-1+ cells were associated with a high level of regulatory CD4+ CD25highCD127–/low and CD8+ CD11b– CD28– lymphocytes. Differences were found in the significance of individual lymphocyte populations for the immediate results of treatment between patients with different subtypes of breast cancer.Conclusion. Determination of lymphocyte subpopulations correlating with the level of PD-1 cells, and the results of treatment in patients with different molecular BC subtypes, will help a clearer understanding of the antitumor immune response in this pathology, and will also serve as a basis for identifying immune biomarkers that can be used as additional predictive factors in various treatment options for BC patients.