For this tudy : patients will be randomized to either :~with administration of peg-G-CSF (administration on D2)~with administration of G-CSF (administration on D4 to D7 or D8)~This study aims to model the effect of exogenous G-CSF for the evolution of polymorphonuclear neutrophils as a function of time and to explain the pharmacodynamic variability during the administration of chemotherapy such as EC-dense dose administered as an adjuvant or neo-adjuvant in patients treated for localized breast cancer.
Patients including of localized breast cancer will require chemotherapy treatment with epirubicin - cyclophosphamide (EC) followed by treatment with docetaxel or paclitaxel. In addition to this chemotherapy, the investigator will prescribe injections of granulocyte growth factors (G-CSF), to stimulate the growth of white blood cells. Patients will be randomized to either a peg-G-CSF arm or a G-CSF arm, prescribed at different times.~The aim is to determine whether one of the two treatment regimens best limits the risk of a decrease in white blood cells