Anlotinib-based Combination Therapy in Patients with Hormone Receptor-positive（HR+） Metastatic Breast Cancer(MBC) .

Inclusion Criteria: * Female patients aged 18 to 75 years, with an ECOG score of 0-1, and an expected survival of at least 3 months; * Presence of measurable lesions as defined by RECIST 1.1 criteria; * Histopathologically confirmed HR-positive/HER2-negative breast cancer. HER2 negativity is determined by an immunohistochemistry (IHC) result of HER2 (0/1+). If the result is HER2 (++), a FISH or CISH test is required to confirm the absence of HER2 amplification; * Patients who have undergone multiple lines of advanced therapy with no remaining standard treatment options; * Prior treatment with at least one line of CDK4/6 inhibitors and endocrine therapy; * Disease progression following aromatase inhibitor (AI) or fulvestrant combined with CDK4/6 inhibitors, either as adjuvant therapy or as systemic treatment for advanced disease. Exclusion Criteria: * Patients with HER2-positive breast cancer confirmed by histology or cytology; * Patients who discontinued therapy due to non-disease progression reasons, such as adverse events or other non-medical factors; * Detection of a second primary malignant tumor at the time of enrollment; * Failure to complete CDK4/6 inhibitor therapy; * Pregnant or breastfeeding patients; * Presence of third-space fluid accumulation (e.g., pleural effusion, ascites, pericardial effusion) that cannot be managed through drainage or other methods; * Patients previously treated with anti-angiogenic agents, including small molecules such as anlotinib or apatinib, and large molecules such as bevacizumab; * Patients currently receiving any other anti-tumor treatment for any other malignancies.