Clinico-biological Data Collection Study of Metastatic Breast Cancer

This prospective study will be conducted on first line metastatic breast cancer patients. Three phenotypic groups are identified on immunohistochemistry done at inclusion: on metastatic sites or breast tumor if local recurrence, usual treatment protocols are often guided by the following groups: * Group 1 : Patients HR (Hormon Receptor) + (E (Estrogen Receptor) + and/or PR (Progesterone Receptor) +) and HER2- (Human Epidermal Growth Factor Receptor-2) * Group 2 : Patients HER2 + with or without HR+ * Group 3 : Patients triple negative (HR- and HER2-) Patients will receive treatments as per standard care according to the patient group. Standard treatments recommended for treatment first line are: 1. For group 1 : For HR + and HER2- patients : * For patients requiring Chemotherapy (visceral crisis), the recommended treatment is : Taxanes based chemotherapy Anthracyclines based chemotherapy * For the patients without visceral crisis: the recommended treatment is : Hormonal therapy combined with CDK 4-6 inhibitors (Cyclin-dependent kinase) as recommended in standard care. 2. For group 2 : HER2 + (with or without HR+), the recommended treatment is : * Paclitaxel (Taxol) combined with Trastuzumab (Herceptin) and Pertuzumab (Perjeta) as per the institutional standard of care. * Docetaxel (Taxotere) combined with Trastuzumab (Herceptin) and Pertuzumab (Perjeta) as per the institutional standard of care. 3. For group 3 : triple negative (HR- and HER2-) patients, the recommended treatment is : * Paclitaxel (Taxol) with or without Bevacizumab (Avastin) as per the institutional standard of care. Further treatment lines are administered according to standard practice. Biological and histological assessments are performed on specific metastasis biopsy samples done at baseline and at each progression. Physical exam, standard laboratory tests, imaging (CT (computerized tomography) scan, PET-CT (Positron emission tomography-computed tomography) and bone scan (for patients with bone metastasis) will be performed every 2 to 6 months according to patient group. Clinical, biological, pathological, epidemiological, socio-economic and multi-omic data will be collected throughout the study duration. These massive data will be used to create new algorithms in order to help clinicians to predict treatment response.