In this study, after at least 4 cycles of taxoid chemotherapy combined with trastuzumab ± pertuzumab, the evaluation result reached SD, CR or PR, and capecitabine combined with pyrotinib + trastuzumab was given successively in the later period (capecitabine was used for 4-6 cycles; Single-arm, multicenter, real-world observational studies using endocrine therapy + pyrrotinib + trastuzumab in patients with HR+, and maintenance therapy after first-line TH (P) therapy for CNS events (if non-CNS recurrent, progressive events occur and the investigator decides to change the follow-up regimen). To evaluate the effect of pyrrotinib combined with trastuzumab in maintaining treatment phase delay/reduction of brain metastases after first-line TH (P) therapy for advanced breast cancer with HER-2 positivity, the incidence of first progression of brain metastases was used as the primary endpoint.
