To our knowledge, this systematic review is the second to evaluate G-CSF andantibiotic use in patients with breast cancer who underwent FEC-D chemotherapy.Overall, median FN rates for patients who receive FEC-D with and without primaryprophylaxis are 10.05% (IQR, 3.8% to 22.6%) and 23.9% (IQR, 9.2% to 27.2%),respectively. The gene discussed is CSF3; the disease is breast cancer.