In two pivotal trials with a similar design, a single fixed dose of pegfilgrastim [6 mg (n = 77) or 100 μg/kg (n = 149) ] was compared with daily filgrastim (5 μg/kg/day; n = 222) as prophylactic G-CSF support in a total of 467 women with breast cancer receiving doxorubicin and docetaxel chemotherapy. This evidence concerns the gene CSF3 and breast cancer.