Pancreatic Elastase 1

This is a prospective cohort study. The investigators enroll subjects with pancreatic ductal adenocarcinoma (PDAC), individuals at high risk for PDAC, patients with other pancreatic diseases, patients with CA19-9 elevation and controls without pancreatic disease. This study aims to establish a diagnostic prediction model by using elastase 1, common clinical serological examinations, and imaging examinations including endoscopic ultrasonography (EUS), and to explore the diagnostic ability of the model in the high-risk population of PDAC. Besides, the investigators search for new biomarkers by multi-omics studies of serum and pancreatic tissues to further improve the diagnostic performance of this model. In conclusion, this study seeks a robust diagnostic prediction model to diagnose PDAC, especially early resectable PDAC.