Research and Analysis of the Mechanisms Involved in the Emergence of Breast Cancer Stem Cells (RepriM)

Patients responding criteria for selection will sign an informed consent form. Before the initiation of chemotherapy, a tumor specimen (under echographic control) and four blood samples will be collected. The chemotherapy consists of 3 cycles of (F)EC100 spaced 21 days apart : * Epirubicin, 100 mg/m² in intravenous (IV) * Cyclophosphamide, 500 mg/m² in IV * +/- 5-fluorouracile (5FU), 500 mg/m² in IV Followed by 3 cycles of Taxotere (Docetaxel, IV, 100 mg/m²) spaced 21 days apart +/- Herceptin (Trastuzumab, IV, 8 mg/kg during C1 and then 6 mg/kg) for 1 year in the case of overexpression of the HER-2 oncoprotein. After 3 cycles of chemotherapy (that is to say at the end of the (F)EC100 treatment, at the time of the usual ultrasound examination), a tumor specimen and four blood samples will be taken. After 6 cycles of chemotherapy (that is to say at the end of the Docetaxel +/- Trastuzumab treatment), four blood samples will be collected. A partial or total mastectomy could be performed during the 6 cycles of chemotherapy. During surgery, a tumor specimen will be taken. The indication of breast surgery will remain at the discretion of the pluridisciplinary committee of the participating center. Prior to the start of treatment, patients will have a clinical and a paraclinical examination and will undergo laboratory examinations. On day 1 of the fourth cycle and after the sixth cycle of chemotherapy, patients will have a clinical examination and will undergo laboratory examinations. After three cycles of chemotherapy, at the time of the intermediate breast ultrasound, patients will have paraclinical examinations. Finally, at the end of the study (after partial or total mastectomy), anatomopathological examinations will be performed on the operative specimen.