Only pegfilgrastim can be used as a single injection; the other two molecules are used according to the chemotherapy protocol on a daily basis so that they cover the nadir of neutropenia [16,17]. In our series, more than 95% of participants prescribed filgrastim, essentially due to its cost, which was the main limiting factor for prescribing G-CSF for primary prevention in 90% of participants. This evidence concerns the gene CSF3 and neutropenia.