Pancreatic ductal adenocarcinoma (PDAC) incidence has increased with a high rate during the past few years (+4.7% per year between 2005 and 2012, source InfoCancer 2013). No cure is currently available for this deadly disease, with an overall survival \<5%. Survival can reach 20% when surgery is possible, giving the best chance to the patients. If patients present locally advance disease, it is crucial to quickly establish resectability to avoid unneeded and even deleterious surgery in patients with metastatic stages. It is also important to increase the rate of true R0 resection with effective preoperative therapy. However, when the cancer is suspected, neoadjuvant chemotherapies are often delayed because the mandatory histologic proof is difficult to make with non-informative biopsies. It is necessary to find new markers to help for rapid diagnosis that could allow neoadjuvant therapies and surgery when anatomo-pathologic proof is not available. New developments in the field of liquid biopsy hold great promise in providing valuable information for diagnosis assistance. The project will be run in two steps. First, several methods will be compared for tumor cell recovery after cell spiking in blood of non-cancer patients and pancreatic cell line onco-exosomes will characterized by flow cytometry. Second the best method will be used to detect and enumerate CTCs in 20 PDAC patients and 20 non-cancer patients. In parallel GPC1+ exosomes from patients' plasmas will be quantified. Diagnosis accuracy will be established and compared. Correlations between circulating tumor elements presence and clinical and biological parameters will be evaluated at the time of the diagnosis. Patient clinical outcome will be assessed according to initial circulating element quantification.
