Studying the Senescent T Cell Features and Its Relationship with the Chemotherapy Efficacy in Young TNBC

This is a single-center observational study that is expected to enroll 30 breast cancer patients and 10 controls from July 2023 to June 2026. We mainly want to investigated senescent T lymphocytes characteristics during neoadjuvant chemotherapy in young triple-negative breast cancer patients. Besides, the relationship between senescent T lymphocytes and neoadjuvant chemotherapy efficacy also of concern to us. Inclusion criteria: (1) female, age ≤40 years old; (2) Invasive breast cancer was confirmed by puncture pathology and TNBC (ER-, PR-, HER2-) was confirmed by immunohistochemistry; (3) Patients who meet the indications of neoadjuvant chemotherapy prescribed in the guidelines. Exclusion criteria: (1) IV patient or history of other malignant tumors; (2) Recently infection or autoimmune disease is not cured or HBV, HIV positive; (3) Had a history of surgery 3 months before enrollment; (4) Patients with insufficient clinicopathological data; (5) Those who do not meet the evidence of neoadjuvant chemotherapy or are unwilling to cooperate. Withdrawal criteria: (1) the subjects did not receive radical surgery in our hospital or were unwilling to continue to participate in the follow-up study; (2) Termination of chemotherapy due to serious side effects or disease progression during chemotherapy; (3) Research data related to the experiment is missing and cannot be supplemented; (4) Poor specimen quality (hemolysis, contamination, etc.); (5) Follow-up lost. Participants will receive 6 cycles of TEC/TAC neoadjuvant chemotherapy, and radical mastectomy after chemotherapy. Clinicopathological data, chemotherapy-related adverse events and prognostic information of patients should be collected during the study. 5ml peripheral venous blood will be collected before chemotherapy, after 2 cycles of chemotherapy, before surgery, and six months after surgery. The senescence phenotype of T lymphocytes will be determined by flow cytometry. The main purpose are: * Studying the senescent features of peripheral T lymphocytes in young TNBC patients receiving neoadjuvant chemotherapy and the relationship with the efficacy of neoadjuvant chemotherapy. * Studying the relationship between senescent T cells and adverse events, DFS and tumor infiltrating lymphocytes.