Detection of Circulating Tumor Cells for the Diagnostic of Pancreatic Adenocarcinoma.

Histological proof is a crucial and necessary step for appropriate care in oncology. In the case of pancreatic cancer, histological proof from pathological analysis of the surgical specimen is very rare due to the limited number (15-20 %) of localized tumor accessible to surgical resection. In most cases, invasive endoscopic explorations are necessary for histological diagnosis before deciding of the most appropriate treatment (palliative chemotherapy or radiochemotherapy). The endoscopic ultrasound with fine needle aspiration (EUS-FNA) is currently considered as the first-line endoscopic procedure for the cytological diagnosis of solid pancreatic tumors. The technique is performed under general anesthesia with sensitivity for the diagnosis of adenocarcinoma of 80% in case of a single procedure and 92% in situations where three different procedures are required. EUS-FNA has to be performed by a physician properly trained for this type of interventional endoscopy. Some severe complications may occur but are relatively rare in expert centers (bleeding, perforation, complications of general anesthesia ...).

Diagnostic alternative approach is biological with research in the peripheral blood of markers of tumor disease. It is possible to detect indirect markers which are molecules produced by tumor tissue (eg CA19.9) and direct markers which reflect the presence of tumor biological material (circulating tumor cells (CTCs) or circulating tumor DNA).

The value of detection of CTCs is not determined for the diagnostic and therapeutic management of pancreatic cancer. Indeed, no study has evaluated the diagnosis performance of circulating markers with EUS-FNA, the reference method for the diagnosis of unresectable forms.