Title Search [BP OP 1-1] Evaluation of postadjuvant therapy for ampulla of vater carcinoma : Multicenter, retrospective study Hyung Sun KIM (Gangnam Severance Hospital, Yonsei University College of Medicine, Korea) [BP OP 1-2] Comparative outcome of laparoscopic and open radical antegrade modular pancreatosplenectomy Sungho KIM (Seoul National University Bundang Hospital, Korea) [BP OP 1-3] Early recurrence following pancreaticoduodenectomy in patients with ampullary cancer Hyeong Min PARK (National Cancer Center, Korea) [BP OP 1-4] Outcome of conversion surgery for initially unresectable bile duct cancer Takashi MURAKAMI (Yokohama City University, Graduate School of Medicine, Japan) [BP OP 1-5] Effect of Vitamin C on postoperative pain after laparoscopic cholecystectomy; A prospective randomized controlled trial Yumi KIM (The Catholic University of Korea Seoul St. Mary's Hospital, Korea) [BP OP 1-6] Validation of AJCC 8th edition stage for gall bladder cancer Dae Joon PARK (Samsung medical center, Korea) [BP OP 1-7] Prognostic factors for hilar cholangiocarcinoma after surgical resection : A retrospective study of survival outcome Jeong Woo LEE (Keimyung University, School of Medicine, Dongsan Medical Center, Korea)