• Age ≥18 years old;

• Invasive breast cancer confirmed by histological or cytological examination, accompanied by metastatic disease; Patients with metastatic diseases not confirmed by pathology or cytology should obtain clear evidence of metastasis through physical examination or radiological research;

• Based on the pathological report of recent biopsy or other pathological specimens (confirmed by the laboratory of the participating research center), the histology and/or cytology are confirmed as triple negative breast cancer. The specific requirements include: a) the definition of negative human epidermal growth factor receptor 2(HER2): the immunohistochemistry (IHC) is 0 or 1+; If IHC was 2+, it was confirmed negative by fluorescence in situ hybridization (FISH). B) Negative estrogen and progesterone receptors means that IHC examination shows ER \< 10% and or PR \< 10%, and the researcher evaluates that patients cannot benefit from endocrine therapy.

• Newly diagnosed brain metastases or brain metastases that have progressed after local treatment: patients with brain metastases who met all the criteria of this scheme before starting from September 1, 2023 and did not meet all the exclusion criteria can also be included;

• Patients must have measurable central nervous system diseases, defined as at least one brain parenchymal lesion, which can be accurately measured in at least one dimension through local radiological examination; And there is no central nervous system symptom or symptom controllable, so radiotherapy is not needed urgently.

• Patients who have previously received at least one taxane and/or one anthracycline antibiotic (as a treatment history of neoadjuvant therapy, adjuvant therapy or metastatic therapy or both);

• Allow (new) adjuvant therapy to have recurrence and metastasis after stopping using Utterone and/or Capecitabine for more than one year, or stop taking drugs for non-progressive reasons in the rescue stage;

• The physical status score (ECOGPS) of the eastern cancer cooperative group is 0-2, and the life expectancy is more than 12 weeks;

• Normal organ and bone marrow function; Blood routine examination was basically normal within one week before joining the group (based on the normal laboratory of each research center): neutrophil count (ANC) ≥ 1.5× 109/L; Hemoglobin (HB) ≥ 90g/L; Platelet count (PLT) ≥ 75× 109/L; Liver and kidney function tests were basically normal within one week before enrollment (based on the normal values of laboratories in each research center): total bilirubin (TBIL)≤1.5× upper limit of normal value (ULN); Alanine aminotransferase (SGPT/ALT)≤2.5×ULN (patients with liver metastasis ≤ 5 XULN); Aspartate aminotransferase (SGOT/AST)≤2.5× upper limit of normal value (ULN); Creatinine clearance rate (Ccr)≥60ml/min.

⁃ Neuropathy should be \< grade 2 within 4 weeks before enrollment (version 5.0 of ncictcae);

⁃ No major organ dysfunction and no heart disease;

⁃ Women and male patients with reproductive potential must agree to use appropriate contraceptive measures before the start of the study and during the study participation.