Palbociclib Combine With Anti-HER2 Therapy in Triple Positive ABC

Inclusion Criteria: * Sign the informed consent form and agree to comply with the requirements of the research protocol * Recurrent or metastatic breast cancer confirmed by histology or cytology that cannot be operated, and has not received systematic treatment for recurrent or metastatic breast cancer. * Estrogen receptor ER is positive (positive staining of ≥ 1% of tumor cell nucleus is positive) and HER2 is positive (immunohistochemistry is 3+, and/or 2+, and ISH is positive) * Age ≥ 18 years old. * ECOG physical status score is 0-1. * Life expectancy ≥ 3 months. * Be in a postmenopausal state. * Suffer from one of the following diseases defined in RECIST 1.1, and the target lesion is not suitable for surgical treatment; The target lesion has not received radiotherapy or relapses in the radiotherapy field: * At least one measurable lesion as the target lesion confirmed by CT or MRI * Non measurable disease with only bone metastasis (osteogenic disease, osteolytic disease or osteolytic osteogenic mixture) * Appropriate hematopoietic function, liver function and kidney function Exclusion Criteria: * Visceral crisis, severe organ dysfunction accompanied by clinical symptoms and signs, and the clinician judges that it is necessary to receive chemotherapy based treatment as soon as possible to obtain disease relief, including but not limited to the following situations: liver metastasis accompanied by a rapid increase of more than 1.5 times of bilirubin or more than 3 t…