1. At the time of signing the informed consent form, 18 years old ≤ 70 years old, female
2. ER positive breast cancer confirmed by pathology: ER positive (≥ 1%) by immunohistochemistry
3. Newly diagnosed advanced patients, including patients with early breast cancer who have evidence of recurrence and metastasis after adjuvant therapy and patients with stage IV breast cancer at the first visit
4. Patients who are willing to receive follow-up treatment in the research center.
You may not be if
1. ErbB-2 gene amplification was recorded by fish (defined as HER2 / CEP17 ratio ≥ 2) or chromogenic in situ hybridization (CISH) or IHC (defined as ihc3 +, or ihc2 + confirmed by fish or CISH) was used to record HER2 positive tumors.
2. Any form of anti-cancer treatment has been carried out for recurrent or metastatic lesions
3. Combined with other malignant tumors or had other malignant tumors in recent 5 years
4. Patients with nervous system disorders caused by diseases or obvious mental disorders will affect patients' right to know, compliance or make them in a dangerous state
5. Patients with life expectancy less than 3 months
