B cell lymphocytes as a potential source of breast carcinoma marker candidates

The prognostic correlation of tumor-infiltrating T cells has been widely studied in breast cancer, but tumor-infiltrating B cells have not received so much attention. The protein profile analysis of CD19+ B-lymphocytes in benign, Luminal A, Luminal B, and triple-negative breast cancer patients in comparison to healthy control via a label-free proteomic quantification was performed. We aimed to find a correlation between immunohistochemical results and proteomic approach in measuring the expression of proteins isolated from B-cell lymphocytes in peripheral blood samples. We identified 18 proteins with a significant fold change of more than 2, that have promising potential to serve as breast cancer biomarkers in the future since they are already either confirmed or proposed markers isolated directly from cancer tissue.