The mean DSN in the absence of G-CSF in breast cancer patients treated with doxorubicin and docetaxel is expected to be 6–7 days [15], while prophylactic treatment with a single fixed 6-mg dose of pegfilgrastim is expected to reduce the mean DSN in Cycle 1 to approximately 1.8 days [14]. This evidence concerns the gene CSF3 and breast carcinoma.