Clinical practice guidelines for duodenal cancer 2025.

Although duodenal cancer is a rare malignancy, its detection has been increasing with the widespread use of upper gastrointestinal endoscopy and advances in diagnostic modalities, and interest in its diagnosis and treatment is growing. Four years after the publication of the first edition of the clinical practice guidelines for duodenal cancer (2021 edition), we have prepared a revised edition that reflects the new findings accumulated during this period. In the field of diagnosis and endoscopic therapy, we further clarified the indications for treatment of non-ampullary duodenal epithelial tumors and provided specific recommendations for biopsy indications. For endoscopic treatment, the indication criteria for endoscopic submucosal dissection (ESD) were stratified according to lesion size and institutional experience, and specific techniques for the prevention of adverse events were presented. In surgical treatment, a new clinical question on minimally invasive surgery was established, and the current status and challenges of laparoscopic and robot-assisted surgery were summarized. In chemotherapy, we emphasized the importance of personalized medicine based on gene panel testing and biomarkers, and incorporated the latest treatment strategies, including immune checkpoint inhibitors. This revised edition is intended to serve as a practical reference in daily clinical practice and to contribute to further improving outcomes for patients with duodenal cancer.