The overall objective of this GUIDE.MRD consortium is to confirm that ctDNA detected after curative intended treatment for PDAC is a marker of residual disease and for risk-of-recurrence, and applicable in clinical practice. Primary objective To confirm that ctDNA analyses performed after PDAC treatment can identify patients with a high risk-of-recurrence. Specifically, the investigators want to determine the association between disease-free survival (DFS) and ctDNA detection status after 1. curative-intended surgery and 2. adjuvant chemotherapy. FRENCH.MRD.PDAC is the French study of the european GUIDE.MRD project