...Patients with advanced recurrent or metastatic breast cancer diagnosed by histology, immunohistochemical detection of HR positive staining cells >= 10% and HER2 negative (receive the latest metastatic tissue sample or previous primary tumor tissue sample test results), menopausal state or receiving LHRH agonist treatment, there is evidence of focal recurrence or metastasis, not suitable for surgical resection or radiation therapy for the purpose of cure; those who meet any of the following can be considered to have reached the menopausal state: (1) Premenopausal/perimenopausal female patients agree to use concomitant luteinizing hormone-releasing hormone (LHRH agonist), and start receiving LHRH agonist treatment at least 28±2 days before the first dose of study dosing can be considered to meet the inclusion criteria3 (Those who have used LHRH agonist for >=21 days but = 60 years; aged = 12 months, follicle-stimulating hormone (FSH) and estradiol (E2) levels in the postmenopausal range without chemotherapy, tamoxifen, toremifene, or ovarian castration within the past year (judged based on the reference range of each research center); (3) For patients aged = 1500/mm^3 (1.5 x 10^9/L); (2) Platelets >= 100000/mm^3 (100 x 10^9/L); (3) Hemoglobin >= 9g/dL (90g/L); (4) Both ALT or AST are l bilirubin (TBIL) =60mL/min (according to Cockcroft and Gault formula); Note: No blood components, hematopoietic-stimulating factors (including granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, erythropoietin, and thrombopoietin, etc.) are allowed within the first 14 days of screening laboratory tests. ...

...Histologically or cytologically confirmed diagnosis of HR-positive (defined as estrogen-receptor ≥ 1%), HER2-negative breast cancer according to analysis of the most recent tumor specimen by local laboratory....

...Patient has pathologically confirmed hormone receptors (HR)-positive (ER+ and/or PgR+) and HER2-negative advanced BC by local laboratory on the last tissue examined....

...- Histologically confirmed HR + / HER2- invasive breast cancer (specific definition: immunohistochemical detection of ER> 10% tumor cell positive is defined as ER positive, PR> 10% tumor cell positive is defined as PR positive, ER and / or PR Positive is defined as HR positive; HER2 0-1 + or HER2 is ++ but negative followed by FISH detection,...

...- Participants must have histologically or cytologically confirmed hormone receptor positive (HR+), HER2 negative metastatic or locally recurrent unresectable invasive breast cancer....

...- Participants with HR-positive HER2-negative locally advanced or metastatic breast cancer....

...2) For breast cancer patients diagnosed as HR-positive and HER2-negative by pathological examination, the expression levels of ER, PR, and HER2 were reported by immunohistochemistry in the primary or metastatic lesions....

...- Postmenopausal, Hormone receptor positive (HR+), HER2 negative breast cancer...

...Diagnosis of hormone receptor positive (HR+), HER2 negative breast cancer....

......

...Histologically confirmed HR-positive, HER2-negative breast cancer patients (receiving the test results of tissue samples from recurrent/metastatic lesions or tissue samples from previous primary lesions, based on the latest test results): a) ER-positive and/or PR-positive defined as: ER/PR-positive staining of tumor cells in ≥ 10% of all tumor cells; b) HER2-negative defined as: standard immunohistochemistry (IHC) test results of 0 or 1+; FISH HER2/CEP17 ratio less than 2.0 or HER2 gene copy number less than 4; 3. ...

Compared with placebo plus fulvestrant, PFS was significantly improved by CDK4/6 inhibitor plus fulvestrant, mTOR inhibitor plus fulvestrant, mTOR inhibitor plus exemestane, and PI3K inhibitor plus fulvestrant, but not HDAC inhibitor plus exemestane….mTOR inhibitor and CDK4/6 inhibitor-based regimens demonstrated superior clinical efficacy and comparable safety profiles as second-line treatment in patients with HR-positive, HER2-negative advanced breast cancer.