Circulating Cancer Cells/Macrophage HYbrid Cells in Patients With Breast Cancer.

"Blood samples will be collected at different times:~* at Baseline for all patients with breast cancer: before initiation of treatment (i.e. before initiation of planned treatment for stage I to III patients and before any new line of treatment for stage IV patients);~* at the time of disease progression (or at 12 months in absence of progression) for patients with metastatic breast cancer (stage IV)~For each patient a tumor sample from the initial diagnosis of the disease (i.e. primary tumor +/- biopsy of a metastasis) will be collected (archived tumor block) for the study."