Abstract

Programmed cell death protein-1 and programmed death ligand-1 pathway activation play a vital role that can be modulated by tumor cells to blunt host immune surveillance. Periphery programmed cell death protein-1 expression level on cluster of differentiation 4⁺ and cluster of differentiation 8⁺ T lymphocytes of 185 female patients first diagnosed with triple negative breast cancer in Tianjin Medical University Cancer Institute and Hospital were analyzed by multicolor flow cytometry prior to any anti-tumor treatment. Patients who received chemotherapy alone for 2-8 cycles and received sequential samples were assessed with response evaluation criteria in solid tumors 1.1. Peripherally, the rate of cluster of differentiation 4⁺ programmed cell death protein-1⁺ and cluster of differentiation 8⁺ programmed cell death protein-1⁺ lymphocytes in general group were significantly higher than in the control group (p<0.0001). Post treatment programmed cell death protein-1 expression level on cluster of differentiation 4⁺ T lymphocytes and cluster of differentiation 8⁺ T lymphocytes was significantly lower than the baseline level in better response to neoadjuvant chemotherapy group (all p<0.05). In the contrary, programmed cell death protein-1 expression on both cluster of differentiation 4⁺ T lymphocytes and cluster of differentiation 8⁺ T lymphocytes showed no difference between pretreatment and post treatment in triple negative breast cancer patients with poor response to neoadjuvant treatment (all p>0.05). Peripheral cluster of differentiation 4⁺ programmed cell death protein-1⁺ and cluster of differentiation 8⁺ programmed cell death protein-1⁺ T lymphocytes of patients with triple negative breast cancer are associated with clinical response to neoadjuvant treatment.