Comparison of Different Methods of CAPTure of Circulating Tumour Cells (CTC) in Patients With Metastatic Breast or Prostate Cancer

"For each patient included, a blood sample will be taken (37 mL in total) for the CTCs detection using the 3 techniques (CellSearch®, Parsortix® and SmartCatch®).~For 3 patients only, an additional blood volume (18 mL) will also be collected for tcDNA detection (exploratory analysis of 3 patients)."