G-CSF Throughout Treatment Reduces Risk of Neutropenia in Breast Cancer

The use of granulocyte colony stimulating factor (G-CSF) throughout treatment with chemotherapy reduces the risk of febrile neutropenia (FN) – severely low levels of immune cells plus fever – compared with its use during only the first cycle of chemotherapy. These results were recently published in the Journal of Clinical Oncology.

Chemotherapy remains an important component for many patients with breast cancer. However, some commonly used chemotherapy agents kill immune cells, resulting in low levels of immune cells (neutropenia) that can leave a patient susceptible to infection. Once a patient has neutropenia, especially FN, a patient can die from a simple cold, as their immune system is not able to fight bacteria, viruses and fungi like a healthy individual.

G-CSF is a drug that stimulates the body to produce immune cells. There are different schedules for using G-CSF during chemotherapy and researchers continue to explore the optimal timing and dosage of G-CSF to keep immune cell levels near normal so infection does not become life-threatening.

Researchers recently conducted a clinical trial to compare different schedules of G-CSF. The trial included 167 women with early breast cancer who were treated with multiple chemotherapy agents. The patients were considered to be at a high risk of developing FN during chemotherapy. One group of patients received G-CSF during the first two cycles of chemotherapy, and the other group received G-CSF during all their chemotherapy cycles.

· 10% of patients who were treated with G-CSF throughout their chemotherapy cycles experienced FN.
· 36% of patients who were treated with G-CSF only during their first 2 cycles of chemotherapy experienced FN.
The researchers concluded that “In patients with early breast cancer at high risk for FN, continued use of primary G-CSF prophylaxis during all chemotherapy cycles is of clinical relevance and thus cannot be abandoned.”

Reference: Aarts M, Peters M, Mandigers C, et al. Primary granulocyte colony-stimulating factor prophylaxis during the first two cycles only or throughout all chemotherapy cycles in patients with breast cancer at risk for febrile neutropenia. Journal of Clinical Oncology. Published online April 29, 2013. doi:10.1200/JCO.2012.44.6229