Ethical statement
The study was an open-label, multi-center, prospective, single-arm, phase II study to evaluate the safety and efficacy of FOLFIRINOX as a first-line treatment for patients with advanced or recurrent BTC. The study protocol was approved by The Clinical Research Review Board of The University of Tokyo (2018006SP), and all patients provided written informed consent before enrollment. This study was conducted in accordance with the Declaration of Helsinki and the guidelines of Good Clinical Practice. And this study was registered in the University Hospital Medical Information Network (UMIN) Clinical Trial Registry (UMIN000020801) and Japan Registry of Clinical Trials (jRCTs 031,180,082).