In recent years, the incidence rate of breast cancer has remained high. In China, breast cancer is the malignant tumor with the highest incidence rate among women. Although the research and development of various targeted drugs and the improvement of clinical treatment system have effectively improved the 5-year survival rate of breast cancer patients in China, the clinical treatment effect of breast cancer is still unsatisfactory. It is speculated that the main reasons for the poor clinical efficacy of breast cancer are drug tolerance, recurrence, distant metastasis, etc., which further leads to some limitations in the exploration of clinical drug development and regulatory mechanism. Paclitaxels are common chemotherapeutic drugs, which have been widely used in the treatment of breast cancer, ovarian cancer and some lung cancer. In2005, albumin binding paclitaxel was approved by FDA for the treatment of breast cancer patients. It is highly hydrophobic and requires a mixture of polyethylene castor oil and ethanol. These solvents will increase the toxic reactions of patients treated with paclitaxel, including severe allergic and anaphylactic reactions, and irreversible peripheral neuropathy, usually requiring the use of corticosteroids and antihistamines in advance.In order to further confirm the advantages of albumin binding paclitaxel and common paclitaxel chemotherapeutic drugs in neoadjuvant chemotherapy of breast cancer, this project intends to explore albumin binding based on different molecular types of breast cancer (luminal a, B, HER2 +, triple negative) An observational study on the efficacy of neoadjuvant chemotherapy with a-paclitaxel and common paclitaxel chemotherapeutic drugs. Randomized grouping confirmed the effectiveness of albumin binding paclitaxel replacing common paclitaxel in neoadjuvant chemotherapy of breast cancer with different molecular types, providing evidence-based medical evidence for the selection of paclitaxel chemotherapeutic drugs based on breast cancer molecular types. At the same time, the patients with poor efficacy among the patients who selected the neoadjuvant chemotherapy scheme for breast cancer according to the guidelines of NCCN and CSCO were screened for clinical transformation research (including basic experimental research, follow-up intensive treatment selection, and providing basis for entering other drug clinical trials). For the patients who achieved the clinical efficacy of PCR with neoadjuvant chemotherapy, we further analyzed the reasons to explore a better scheme of neoadjuvant chemotherapy.

Inclusion Criteria:

• 1. Female breast cancer patients aged ≥ 20 years and ≤ 70 years, with informed consent and meeting the treatment standard of neoadjuvant chemotherapy scheme; 2. Invasive breast cancer with TNM stageT2-4N0-3M0; 3.No treatment for breast cancer before enrollment, such as chemotherapy, targeted therapy and endocrine therapy; 4.All patients underwent thick needle biopsy of breast tumors (patients suspected of axillary lymph node metastasis should undergo lymph node biopsy) to determine the status of ER, PR, HER-2 and Ki-67; 5. All patients had normal cardiopulmonary function, liver and kidney function.

Exclusion Criteria:

• 1. The patient does not cooperate and is unwilling to sign the informed consent form; 2. The tumor has been confirmed to have distant metastasis; 3. Antitumor therapy, hormone replacement therapy and other breast cancer related treatments were performed before enrollment; 4. Any other malignant tumor is combined; 5. Patients with active infection, HIV history or chronic hepatitis B or C; 6. Persons with abnormal heart and lung functions or liver and kidney functions; 7.Other clinical researchers in recent 3 months.

Breast cancer patients with TNM stage T2-4N0-3M0 who were hospitalized in the breast surgery department of Shandong Qianfoshan Hospital from the time when the ethical approval document was obtained to December 2024.