Adjuvant chemotherapy of S-1 versus S-1 plus metformin for resected pancreatic cancer: A multicenter and randomized phase II trial.

TPS474Background: Adjuvant chemotherapy with S-1 in patients with resected pancreatic ductal adenocarcinoma (PDAC) improved the 5-year survival rate to 44.1% and therefore has been a standard of care in Japan. Recent epidemiologic data has revealed possibility of metformin (a drug for type II diabetes) improving the prognosis of PDAC. In this context, we compare the efficacy and safety of S-1 plus metformin with S-1 alone as adjuvant chemotherapy in patients with resected PDAC. Methods: This multicenter-randomized-phase II study is conducted at 29 institutions in Japan (Registry Number; UMIN000020681). Key eligibility criteria are age 20 years or more with good performance status; histologically proven PDAC of stage I-II without macroscopic residual tumor. Patients receiving preoperative treatment for PDAC and previously treated with DPP-4 inhibitor, GLP-1, and metformin are excluded. After giving written consent to the study, patients are randomly assigned either study group (S-1 plus metformin) or contr...