27 June 2019Breast cancer is the most common malignant tumor in women and the leading cause of malignant tumors in women worldwide, which seriously threatens a woman’s health. Chemotherapy is an important systemic adjuvant therapy and plays an role in the overall treatment of breast cancer. While improving overall survival and disease-free survival, chemotherapy drugs can also cause a series of adverse reactions. Neutropenia is considered the most severe hematological toxicity caused by chemotherapy and is the most common dose-limiting toxicity [1]. Elderly women with triple-negative breast cancers, having a poor prognosis and high risk of recurrence, are faced with high-intensity and multi-cycle postoperative chemotherapy. This will cause their bone marrow reserve and hematopoietic function to decline, with increasing occurrence of chronic underlying diseases such as hypertension and coronary heart disease. There will be a significant increase in the risk of severe neutropenia and infection after chemotherapy, and an increase in the risk of death due to discontinuation of chemotherapy. Therefore, prevention of neutropenia is important to the smooth progress of chemotherapy. The use of recombinant human granulocyte colony-stimulating factor (rhG-CSF) is a significant milestone for chemotherapy of malignant tumors [2]. It can stimulate the release of bone marrow to the peripheral blood, reduce the incidence of infection caused by the inhibition of hematopoiesis of bone marrow after chemotherapy, and ensure the completion of chemotherapy. Therefore, rhG-CSF is an effective drug for the prevention of neutropenia in tumor patients receiving chemotherapy and radiotherapy [3–4]. RhG-CSF has been widely used in clinical practice [5]. However, because plasma half-life is short, which leads to consecutive days in one chemotherapy period, rhG-CSF use causes inconvenience and suffering to patients [5–6]. Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) is a long-acting rhG-CSF which acts on hemopoietic stem cells, stimulates the proliferation and differentiation of mononuclear granulocyte progenitor cells after binding to cell-specific surface receptors, and plays a role in simultaneously activating terminal cells. Additionally, its half-life is long and convenient for use, which increases the clinical application for the chemoprevention of neutropenia [7]. This study was aimed at the prevention of neutropenia in elderly patients with breast cancer who needed intensive chemotherapy. Among them, 25 patients treated with PEG-rhG-CSF exhibited positive effects and safety in preventing neutropenia.