Sacituzumab Govitecan + Toripalimab as First - Line Therapy for Advanced Triple - Negative Breast Cancer and Biomarker Exploration

Inclusion Criteria: 1. Female breast cancer patients aged 18 to 75 years old; 2. Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score: 0 to 1; 3. Patients with histologically or cytologically confirmed advanced triple-negative breast cancer; 4. Patients who have not received systemic treatment (including chemotherapy, targeted therapy and immunotherapy) for advanced triple-negative breast cancer; 5. According to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 standard, having at least one measurable lesion; 6. Deciding to receive anti-tumor treatment with the combination of sacituzumab govitecan and toripalimab. Exclusion Criteria: 1. Patients with symptomatic brain metastases (such as increased intracranial pressure, epilepsy, etc.) who require emergency radiotherapy or surgical intervention; 2. Patients who have previously received HER2-targeted therapy or Trop-2-targeted therapy; 3. Patients who have previously used or are currently using PD-(L)1 inhibitors and/or ADC drugs containing topoisomerase inhibitors, such as sacituzumab govitecan, Dato-DXd, etc., as well as topoisomerase inhibitors; 4. Patients who are considered by the investigator to be unsuitable for participating in this study.