BACKGROUND Despite emerging evidence supporting circulating tumor DNA (ctDNA) as a potential biomarker for pancreatic ductal adenocarcinoma (PDAC), its clinical efficacy for serial monitoring has not been thoroughly explored. We hypothesized that serial monitoring of ctDNA provides clinically relevant information on treatment response and prognosis in patients with PDAC. AIM To investigate the feasibility of using longitudinal ctDNA monitoring to predict treatment response and prognostic outcome