Wen C, Deng XX, Ren D, et al. - This retrospective study was undertaken to investigate the link between molecular characteristics and clinical outcomes of pancreatic ductal adenocarcinoma (PDAC) patients, to ultimately ascertain the genomic determinants of the recurrence and prognosis of PDAC following surgical removal. Participants included 181 PDAC patients who underwent pancreatectomy and adjuvant chemotherapy, with 67 patients in the training set. The results were validated using an internal validation set of 48 patients and an external validation set of 66 patients. Significant disparities in tumor copy number instability (CNI) levels were evident between the late recurrence (LR) group and early recurrence group. Experts identified as well as validated the link between CNI and clinical result in 181 patients with resectable PDAC in this study, showing the usefulness of lower tumor CNI levels as biomarkers of postoperative LR and favorable prognosis. Enhanced predictive accuracy was conferred by the combination of CNI and lymph node metastasis status, as well as strategies for patient stratification were illuminated.