In solid cancers, some more aggressive tumor cells actively detach from the primary lesion and then travel through the circulating compartment to reach distant organs and form micro-metastases. These circulating tumor cells (CTCs) that have become disseminated tumor cells (DTCs) flourish in their new environments and may remain dormant for many years after the complete resection of the primary tumor. Detecting CTCs in the blood is also relevant for assessing tumor progression, prognosis and therapeutic follow-up. The non-invasive, highly sensitive for CTCs analysis is called liquid biopsy. Pancreatic adenocarcinoma and breast cancer remain among cancers of very poor prognosis and thus represent a major therapeutic challenge. In recent years, the Axl membrane tyrosine kinase receptor has been the target of growing interest. Activation of the Gas6/Axl signaling pathway is associated with, among other things, tumor cell growth and survival, epithelial to mesenchymal transition (EMT) or drug resistances. In addition, Axl overexpression is frequently identified in patients with pancreatic adenocarcinoma and is associated with a poor prognosis. For example, the Laboratoire des Cellules Circulantes Rares Humaines (LCCRH) at the CHU and the University of Montpellier has developed two new CTC-AXL tests to detect CTCs expressing Axl: one using the CellSearch® (gold standard and FDA-approved) system and the other using the EPIDROP technique. The purpose of this research project is to assess the concordance of the CTC-AXL measurement by the innovative EPIDROP technique and the CellSearch® technique in patients with metastatic pancreatic or breast cancer.