Immunological characteristics of primary tumor and bone marrow in patients with breast cancer

Abstract

Introduction. The Implementation of immunotherapy in cancer requires a thorough analysis of the biological characteristics of the tumor. Therefore, the study of tumor immunophenotype is the leading scientific direction. Molecules of the major histocompatibility complex are considered as promising markers for evaluating the possibility of using immunotherapy. Objective. To study the immunophenotype of the primary tumor in molecular subtypes of breast cancer and analyze it depending on the frequency of bone marrow damage. Materials and methods. The study included 99 patients with breast cancer. Tumor tissue and bone marrow samples were studied. Stages: T1 (51.5%), T2 (44.4%), T3 (2.0%). Metastatic involvement of lymph nodes (N+) was noted in 39.4% (n = 39) of cases. Immunophenotyping of the tumor was carried out on cryostat sections by immunofluorescence. Antibodies to HLA-I, HLA-II, KL1, FITC-labeled F(ab2) antiserum fragments (Becton Dickinson, USA) were used. The bone marrow was studied by morphological (Zeiss microscope, Axioskop, Germany) and immunological methods (flow cytometry, FACS Canto II, USA), data analysis – Kaluza Analysis v2.1 software. Used monoclonal antibodies: CD45, EPCAM (Becton Dickinson, USA). Statistical data processing was performed using the IBM-SPSS Statistics 21 package. Results . The HLA-I antigen is absent or expressed by single tumor cells in 50.8% of cases of luminal breast cancer. Pronounced or partial expression was noted in 36.9% of cases. With the Erb-B2 subtype, all samples had the expression of antigens of the HLA-I class. Loss of HLA-I antigen or weak expression was observed in 30% (3/10) of cases of the triple-negative subtype, in the same percentage of cases the expression of HLA-II molecules was noted. There were no significant differences in the expression of HLA molecules between subtypes. Using flow cytometry, bone marrow involvement was detected in 40% (26/65) of cases. There were no significant relationships between bone marrow damage and the size of the primary tumor, stage, grade of breast cancer, or expression of HLA molecules. Conclusions. The expression of HLA molecules does not differ in significant differences depending on the biological subtype. The frequency of bone marrow damage did not depend on the expression of HLA-I, class II molecules.