The purpose of this study is to assess the effect of pyrotinib

The purpose of this study is to assess the effect of pyrotinib combined with trastuzumab in the maintenance phase delay/reduction of brain metastases after first-line TH(P) therapy for HER-2-positive advanced breast cancer

Inclusion Criteria:

1. age:18-75 years old, female;
2. HER2 positive advanced breast cancer diagnosed by pathology, cytology or radiology, including inoperable breast cancer with stage IV, or recurrent/metastatic breast cancer.HER-2 positivity was confirmed by histopathological test: immunohistochemistry(IHC) results of 3 + or in situ hybridization (ISH) results of amplification of HER2;
3. Disease progression occurs after treatment with trastuzumab (stopping the drug for more than 12 months) or newly diagnosed IV stage breast cancer patients;
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1;
5. Life expectancy greater than or equal to 6 months;
6. The main organs function well, and the inspection indicators meet the following requirements:

1) For results of blood routine test HB≥90g/L; ANC≥1.5×109/L; PLT≥90×109/L; 2) For results of blood biochemical test ALT and AST≤2×ULN, but≤5×ULN if the transferanse elevation is due to liver metastases； TBIL≤1.5×ULN； Serum creatinine ≤1.5×ULN; 7. The researchers believed that the subjects were preference to benefit; 8. Participants were willing to join in this study, and written informed consent.

Exclusion Criteria:

1. Patients with brain metastases by CT or MRI;
2. More factors affecting of oral drugs (gastrointestinal surgery history, inability to swallow, chronic diarrhea, intestinal obstruction);
3. Study drug and excipient allergy;
4. History of psychiatric drugs abuse and can't quit or patients with mental disorders;
5. Pregnant or lactating female patients;
6. Less than 4 weeks from the last clinical trial;
7. The researchers think inappropriate.