Chemotherapy is an important means to prolong the survival time of advanced breast cancer. As a new type of microtubule inhibitor, eribulin has a unique mechanism of action. Compared with single drug chemotherapy, it can improve the overall survival time of 2.5 months, increase the clinical benefit rate by 5 times, and the tolerance of eribulin is good. Therefore, the guidelines at home and abroad recommend eribulin for the rescue of advanced breast cancer.

However, up to now, there is no large sample data on the efficacy of eribulin combined with anti HER2 targeted therapy in HER2 + metastatic breast cancer, and the efficacy of combined immunotherapy in triple negative metastatic breast cancer. Moreover, as a newly marketed chemotherapy drug in China, the efficacy and safety data of eribulin in Chinese population are relatively lacking. Therefore, we plan to include different types and line numbers of advanced breast cancer patients based on the Chinese population through real-world research, and receive the treatment regimen containing eribulin respectively. In HR + / her2-mbc, we use eribulin monotherapy; in HER2 + MBC, we use eribulin + anti HER2 targeted therapy; in TNBC, we use eribulin + immunotherapy / chemotherapy, The efficacy and safety of eribulin were evaluated.

Inclusion Criteria:

1. Adult female patients (aged 18-80 years, including 18 and 80 years) with metastatic breast cancer confirmed by pathology or imaging are not suitable for surgical resection or radiotherapy for the purpose of cure;
2. The starting time of eribulin treatment was between January 2021 and December 2021;
3. They received no more than 2-line chemotherapy in the past;
4. In HR + / her2-mbc, patients were treated with eribulin monotherapy; in HER2 + MBC, patients were treated with eribulin + anti HER2 targeted therapy; in TNBC, patients were treated with eribulin + immunotherapy / chemotherapy; in patients with HER2 + MBC, patients were treated with eribulin + immunotherapy /chemotherapy;

Exclusion Criteria:

1. Patients without pathological diagnosis;
2. Patients with central nervous system metastasis;
3. She has received more than two chemotherapy regimens for metastatic breast cancer;
4. Participating in any intervention drug clinical trials.
5. Those who have been known to have allergic history to the components of this regimen;
6. The patient, the patient, or the person with serious harm to the safety of the study.
7. Any other situation in which the researcher considers that the patient is not suitable for the study may interfere with the concomitant diseases or conditions involved in the study, or there are any serious medical barriers that may affect the safety of the subjects (e.g., uncontrollable heart disease, hypertension, active or uncontrollable infection, active hepatitis B virus infection)

Adult female patients (aged 18-80 years, including 18 and 80 years) with metastatic breast cancer confirmed by pathology or imaging are not suitable for surgical resection or radiotherapy for the purpose of cure