A Study of Fluvestrant Combined With Oral Vinorelbine in Hormone Receptor-positive Advanced Breast Cancer

Inclusion Criteria: * Age between 18 and 75 year-old women; Pathologically or cytologically confirmed breast cancer; Hormone receptor-positive * ECOG score: 0-1, expected survival time ≥ 3months; * Recurrence after adjuvant therapy or metastatic breast cancer and chemotherapy naïve in the metastatic setting or had one prior regimen for metastatic breast cancer. * Patients must have measurable disease according to RECIST criteria Version 1.1. Bone metastases lesions were excluded. * The patients have adequate hematologic and organ function. Exclusion Criteria: * Patients with symptomatic brain metastases. * Patients who are known or suspected to be allergic to the active ingredient or excipients of the investigational drug. * Received ≥1 standard chemotherapy regimen (excluding endocrine therapy) for advanced breast cancer. * Participation in other clinical trials within 4 weeks before enrollment. * Severe cardiovascular disease, including history of congestive heart failure, acute myocardial infarction within 6 months before enrollment, transmural myocardial infarction measured by ECG, uncontrolled arrhythmia, angina requiring therapy, clinically significant valvular heart disease, uncontrolled hypertension. * Severe or uncontrolled infection. * Any factors that affect the oral administration and absorption of drugs (such as inability to swallow, gastrointestinal resection, chronic diarrhea and intestinal obstruction, etc.); * Active malignancy in the past 5 years (other than carcinoma in situ of the cervix or basal cell carcinoma of the skin). * Patients who are pregnant , breastfeeding ,or refuse to use adequate contraception during the course of participation. * Need to concurrent other cancer therapy(other than palliative care for non-target lesions). * Other ineligible conditions according to the researcher's judgment.