The goal of this observational study is to learn about the features of senescent T lymphocytes induced by chemotherapy and its relationship with the efficacy of neoadjuvant chemotherapy in young triple-negative breast cancer (TNBC) patients.

The main questions it aims to answer are:

• What are the senescent features of peripheral T lymphocytes in young TNBC patients receiving neoadjuvant chemotherapy and the relationship with the efficacy of neoadjuvant chemotherapy?

• What is the relationship between senescent T cells and adverse events, DFS and tumor infiltrating lymphocytes?

  1. Participants will receive 6 cycles of docetaxel + adriamycin/epirubicin + cyclophosphamide (TEC/TAC) neoadjuvant chemotherapy, and radical mastectomy after chemotherapy.

2.5ml peripheral venous blood will be collected before chemotherapy, after 2 cycles of chemotherapy, before surgery, and six months after surgery.

3.Clinicopathological data, chemotherapy-related adverse events and prognostic information of patients should be collected during the study.

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.

Inclusion Criteria:

1. Female, age≤40 years old,
2. Invasive breast cancer confirmed by pathology, immunohistochemistry showed TNBC (ER-, PR-, HER2-),
3. Indications for neoadjuvant chemotherapy according to guidelines: tumor diameter > 2cm or with axillary lymph node metastasis or desiring breast-conserving surgery but should obtain negative surgical margins through neoadjuvant chemotherapy.

Exclusion Criteria:

1. Stage IV patients or a history of other malignancies,
2. Having microbial infection or autoimmune disease have not been cured or having HBV, HIV infection,
3. Having surgery 3 months before enrollment,
4. Patients with insufficient clinicopathological data,
5. Does not meet the indications for neoadjuvant chemotherapy or is unwilling to cooperate.

young triple negative breast cancer patients receiving neoadjuvant chemotherapy