Gemcitabine Combined With Eribulin Regimen in the Treatment of Second-line Above Recurrent HER2-negative Breast Cancer

Inclusion criteria 1. Histologically diagnosed histological examination confirmed breast cancer patients with locally advanced or metastatic HER2-negative (expression lack of human epidermal growth factor 2 (HER2) confirmed by central laboratory examination) and unsuitable for surgical treatment; 2. Received first-line or above systemic therapy in the past, with disease progression after the last treatment, and have used anthracyclines and/or taxanes, and currently there is no standard treatment regimen; 3. Must have at least one evaluable lesion according to RRECIST version 1.1 criteria (the longest diameter on spiral CT is at least 10mm, and the longest diameter on ordinary CT is at least 20mm); 4. Female, 18 years old ≤ aged ≤75 years old; 5. ECOG PS 0\~2 points; 6. Expected survival period ≥ 3 months; 7. Sufficient blood function: absolute neutrophil count (ANC) ≥1.5×109/L, platelet count ≥ 80×109/L and hemoglobin ≥ 8g/dL; 8. Sufficient liver function: total bilirubin ≤ 1.5 times the upper limit of normal (ULN); AST and ALT ≤ 2.5 times the upper limit of normal (ULN); alkaline phosphatase ≤ 5 times the upper limit of normal (ULN); 9. Sufficient renal function: serum creatinine ≤ 1.5 times the upper limit of normal (ULN) or calculated creatinine clearance ≥ 50 mL/min; 10. The electrocardiogram is basically normal; 11. Women with an intact uterus must have a negative pregnancy test result within 28 days prior to enrollment in the study (unless it has been 24 months of amenorrhea). If the pregnancy test is more than 7 days from the first dose, a urine pregnancy test is required for verification (within 7 days before the first dose); 12. Have not received radiotherapy, chemotherapy, targeted therapy and other treatments within 4 weeks before enrollment; 13. Signed the informed consent. Exclusion criteria (Subjects can not enter the study if they meet any of the following conditions) 1. Pregnant, lactating women, or female patients who are fertile but not taking contraceptive measures; 2. Existing severe acute infection that has not been controlled; or purulent and chronic infection with persistent wound healing; 3. Patients with original serious heart disease, including: congestive heart failure, uncontrolled high-risk arrhythmia, unstable angina pectoris, myocardial infarction, severe heart valve disease and resistant hypertension; 4. Those with bleeding tendency; 5. Individual with mental disorders/individual who cannot obtain informed consent; 6. Patients who use drugs and alcohol for a long time, which affects the evaluation of the test results; 7. Other conditions in which the investigator believes that the patient should not participate in this trial.