Does immune cell boosting drug G-CSF reduce the effects of chemotherapy in different cancers?

This study examined the effects of granulocyte colony-stimulating factor (G-CSF) given as a preventative measure in patients with high- and medium-risk cancer receiving chemotherapy. The results showed that preventative G-CSF allowed more patients to complete chemotherapy treatment and lowered patients’ chances of developing secondary tumors.

Different types of chemotherapy are used to treat cancer. Some types of chemotherapy kill immune cells as a side effect. Neutropenia is the term for low immune cell levels. This can cause further complications for patients, including being too ill to complete chemotherapy treatment. 

Therefore, it is important to identify and prevent neutropenia in patients who are at high or medium risk.
There are several factors that increase a patient’s risk of developing neutropenia. These include being over 65, having kidney problems, heart disease, diabetes or HIV.  G-CSF also called filgrastim (Neupogen), is a drug that can boost immune cell levels. It is given to patients before a chemotherapy dose to prevent neutropenia. It is unknown if preventative G-CSF increases the number of patients with different cancer types who complete chemotherapy treatment.

22868 patients who received chemotherapy were analyzed. Of these, 11513 patients had breast cancer, 4273 patients had lung cancer, 3765 patients had colorectal cancer, 2030 had non-Hodgkin lymphoma and 1287 patients had ovarian cancer. Patients were analyzed based on whether they had received preventative G-CSF or not.

Of the patients, 36.8% were considered high risk for neutropenia and 63.2% were considered medium risk. 76.1% of patients with high-risk and 28.2% with medium-risk received preventative G-CSF.

Of all patients with medium risk, 20.2% developed secondary tumors after receiving G-CSF compared to 35% of patients who did not receive G-CSF. 

There are two methods of giving G-CSF: direct injection and an on-body injection device. 60.6% of patients who used the on-body injection device finished all chemotherapy cycles, compared to 52.2% of patients who used the direct injection. 

The authors concluded that preventative G-CSF increases the number of patients who complete chemotherapy and this reduces the development of secondary tumors. The authors commented that preventative G-CSF is not used enough in high and medium risk patients.

The manufacturer of filgrastim G-CSF, Amgen, funded this study. This study used data from medical records. This means that not all information was present for all patients, such as the dose of chemotherapy.