The purpose of this study is to evaluate the safety and efficacy of PEG-rhG-CSF in preventing chemotherapy-induced neutropenia

Neutrophilic granulocytopenias is one of the most common and most serious complications in chemotherapy. Research shows that about 25% ~ 40% in patients receiving standard chemotherapy can appear neutropenia with fever. It can increase the risk of infection and Chemotherapy related death, and lead to the delay of chemotherapy, and maybe Reduce the curative effect of chemotherapy. RhG-CSF has widely used to prevent neutropenia, but its half-time is short, and need daily injections to maintain the effective blood drug concentration. Patients are with poor compliance, related adverse reaction and medical costs increase. At the same time, some patients appear neutropenia thought RhG-CSF is given. Therefore, how to reduce the frequency of RhG-CSF injections and more effectively prevent neutropenia more effectively, on the premise of ensure the safety of patients to achieve better effect of chemotherapy, has always been the focus of the clinical problem.

Pegylated recombinant human granulocyte-colony stimulating factor(PEG-rhG-CSF) is a first class national new drug developed by domestic pharmaceutical companies. According to some phase Ⅱand phase Ⅲ clinical trials, PEG-rhG-CSF has a good effect. The patients need only one injection for PEG-rhG-CSF each Cycle of chemotherapy, and the effect of rising white blood cell is more smoothly, and it can avoid pain of repeated injection of PEG-rhG-CSF

Inclusion Criteria:

1. Provision of informed consent Histologically proven breast cancer
2. Patients need to accept many cycles chemotherapy alone
3. appears III/IV neutropenia after last cycle of chemotherapy, and plan in the subsequent cycle using the same chemotherapy program.
4. KPS≥70
5. Lifetime is expected to more than 3 months
6. Before enrollment,ANC≥ANC ≥1.5×109 /L,Platelet Count (PLT) ≥80×109 /L, White Blood Cell （WBC ）≥3.0×109 /L.
7. Sign Informed Consent Form （ICF）.

Exclusion Criteria:

1. There is any difficult to control infection, or within 72 h before chemotherapy received antibiotic treatment systematically
2. Any abnormal bone marrow hyperplasia and other hematopoietic function was abnormal
3. Suffer from other malignant tumor was not cured, or patients with brain metastasis
4. Total Bilirubin （TBIL）,Alanine Transminase （ALT）,Aspartate aminotransferase(AST)>2.5×ULN
5. Cr>1.5×ULN
6. Be allergic to this product or other genetically engineered e. coli sources of biological products
7. Mental or neurological disorders
8. Women with pregnancy or lactation; The childbearing age women refused to accept contraception
9. The investigators think that the person doesn't fit into the group