The general term triple negative breast cancer refers to triple negative ductal carcinoma (ER, PR, HER2 all negative), which is still pathologically mixed, of which about 80% are basal cell-like breast cancer, all with poor prognosis. Clinical characteristics: 1. young patients; 2. early metastasis; 3. rapid progression; 4. EGFR, CK5/6 positive. Triple-negative breast cancer metastasis sites: lung 40%; liver 20%; brain 30%; bone 10%. The metastatic sites of non-triple-negative breast cancer: lung 20%; brain 10%; liver 30%; bone 40%. Bone metastases alone without other metastases are very rare in metastatic breast cancer. Some specific types of triple-negative breast cancer, such as medullary, septic and adenoid cystic carcinoma, have a better prognosis.