PDAC patients are categorised as resectable, borderline resectable, locally advanced, metastatic and recurrent. Substantial neoplastic tissue is only available for the resectable group. This is unfortunate as the other groups are those that would benefit the most from molecular characterization and identification of markers, which may be predictive and/or provide therapeutic stratification. For these categories of patients, only fine needle aspiration or small biopsies could be obtained until now. However, the introduction of new needles, specifically designed to acquire larger high quality biopsy samples under endoscopic ultrasound (EUS), has now made it possible to test prognostic, predictive and therapeutic stratification markers. However, the applicability of EUS-fine needle biopsy (EUS-FNB) samples for this purpose has yet to be clinically validated. The working hypothesis of this proposal is that the molecular sub-classification of PDAC on EUS-FNB tissue samples could be applied for prognostic stratification and therapeutic decision strategies in both resectable and unresectable patients using DNA and RNA biomarkers.