GATA6 Expression as a Predictor of Response to Peri-Operative Chemotherapy in Resectable Pancreatic Adenocarcinoma

Inclusion Criteria: * Patients with a histological diagnosis of PDAC. Those with unconfirmed histology must have this confirmed by EUS-FNB in the pre-screening period prior to commencement of chemotherapy. Invasive PDAC in the setting of intraductal papillary mucinous neoplasm (IPMN) is permitted. * Patients must consent to EUS-FNB for correlative analysis even if adenocarcinoma has been confirmed, unless confirmation was performed using a previous biopsy or fine needle biopsy with adequate tumour tissue for GATA6 analysis. * Resectable primary tumour on preoperative biphasic (arterial and venous phases) contrast-enhanced CT for pancreatic staging as per institutional standard of care, with ≤5 mm slice thickness. MRI for liver metastases (optional) as per institutional standard of care. The definition of resectability (as per NCCN guidelines - see Appendix B) includes: * no involvement of the celiac artery, common hepatic artery or superior mesenteric artery (or if present a replaced right or common hepatic artery) * no involvement or \<180 (interface between tumour and vessel wall, of the portal vein or superior mesenteric vein, and patent portal vein/splenic vein confluence\_ * For tumours of the body and tail of the pancreas, involvement of the splenic artery and vein of any degree is considered resectable disease * Patients must be medically fit to undergo surgical resection * No prior oncological treatment for index PDAC * ECOG Performance status 0-1 * Age \> 18 …