This study evaluated the feasibility and reliability of PDAC molecular subtyping on tissue core biopsies samples acquired under EUS guidance. Moreover, this study will assess the impact of molecular subtypes assessed on EUS-FNB samples in patients with resectable and unresectable (locally advanced, advanced, and metastatic) PDAC undergoing chemotherapy on treatment response and survival and the utility in monitoring disease response to therapy and early occurrence of disease relapse using the TaqMan RNA assay in serum

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.

Inclusion Criteria:

• Patients referred to EUS with FNB in the suspect of pancreatic cancer
• Availability of biopsies obtained during EUS-FNB
• Histological diagnosis of pancreatic ductal adenocarcinoma of any stage
• Age >18 and <80 years
• Willing to be followed up at the Fondazione Policlinico A. Gemelli University Hospital
• Able to sign informed consent

Exclusion Criteria:

• Histological diagnoses other than pancreatic ductal adenocarcinoma
• Pregnancy or lactation
• Unable to sigh informed consent

This study concerns consecutive individuals with a solid pancreatic lesion who will undergo diagnostic EUS-FNB. Those with a histological diagnosis of PDAC will be enrolled in the study. Enrollment will include patients with resectable disease and those with unresectable disease, which can be divided in different stages, i.e. borderline resectable, locally advanced, advanced, and metastatic.