This study is an observational study that retrospectively collects data of triple-negative breast cancer patients who received neoadjuvant therapy. It compares the bpCR rate, apCR rate, and tpCR rate of patients treated with chemotherapy or immunotherapy, in order to analyze the efficacy and influencing factors of chemotherapy and immunotherapy in neoadjuvant therapy for triple-negative breast cancer.

Breast cancer is one of the most common malignant tumors in women, with a rapidly increasing incidence rate and mortality rate globally. Triple-negative breast cancer (TNBC) refers to a type of breast cancer that lacks amplification of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2), accounting for approximately 15% to 20% of all breast cancer types. It is characterized by high aggressiveness, rapid recurrence and metastasis, difficult treatment, and high mortality rate. The main treatment methods for TNBC include chemotherapy, surgery, and neoadjuvant therapy. Neoadjuvant therapy is an important component of TNBC treatment, which can rapidly control tumor burden, reduce the risk of distant metastasis, increase surgical opportunities, and facilitate preoperative assessment of tumor response to drugs, thereby evaluating the effectiveness of treatment regimens and guiding the selection of postoperative treatment plans. Currently, the standard neoadjuvant therapy regimen for TNBC is based on chemotherapy combined with immunotherapy or targeted therapy.

In recent years, the application of immunotherapy in triple-negative breast cancer has gained increasing attention. Based on the phase III clinical study KEYNOTE-522, the PD-1 inhibitor pembrolizumab has been approved for neoadjuvant and adjuvant therapy of triple-negative breast cancer.

Preliminary data from the KEYNOTE-522 study indicate that, in neoadjuvant therapy, the combination of pembrolizumab significantly improves the pathologic complete response (pCR) rate and 3-year event-free survival (EFS) rate compared to chemotherapy alone. The study results suggest that immunotherapy has advantages in improving the prognosis of triple-negative breast cancer.

This study retrospectively collected data on triple-negative breast cancer patients who received neoadjuvant therapy based on inclusion and exclusion criteria, including complete data on diagnosis age, clinical tumor stage, clinical lymph node stage, Ki-67 level, HER-2 expression, surgical method after neoadjuvant therapy, and postoperative pathology. The study categorized neoadjuvant efficacy into breast pathological complete response, axillary pathological complete response, and overall pathological complete response. It compared and analyzed the bpCR rate, apCR rate, and tpCR rate of patients with different clinical characteristics to evaluate the efficacy of chemotherapy and immunotherapy in neoadjuvant therapy for triple-negative breast cancer. Binary logistic regression analysis was used to investigate the influencing factors of neoadjuvant efficacy. Additionally, this study established a set of subgroup analyses to explore the efficacy and influencing factors of albumin-bound paclitaxel weekly therapy and three-week therapy in immunotherapy.

Inclusion Criteria:

• (1)The patient is aged ≥18 years;(2) Both the biopsy pathology and postoperative pathology confirm the diagnosis of triple-negative breast cancer; (3) The patient has undergone complete neoadjuvant therapy; (4) After neoadjuvant therapy, the patient underwent surgical treatment and has complete postoperative pathology results; (5) The patient's basic information is complete.

Exclusion Criteria:

• (1) Bilateral breast cancer or distant metastasis; (2) History of previous malignant tumor or chemotherapy/immunotherapy; (3) Required NST not completed or no surgical treatment after NST; (4) Lack of pathological evaluation results for biopsy specimens or postoperative specimens, or postoperative pathological results not being triple negative; (5) Unable to obtain characteristic patient information, such as age and tumor stage. (6) Change in regimen during neoadjuvant therapy; (7) Lost to follow-up patients.

TNBC patients