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.