1. Department of Surgery and Cancer Research Institute; Seoul National University College of Medicine; Seoul; Korea
2. Department of Surgery I; Oita University Faculty of Medicine; Oita; Japan
3. Department of Surgery; Seoul National University Bundang Hospital; Seongnam; Korea
4. Department of Gastroenterological Surgery; Cancer Institute Hospital, Japanese Foundation for Cancer Research; Tokyo; Japan
5. Department of Surgery; Fujita Health University School of Medicine; Aichi; Japan
6. Department of Surgery; Yonsei University Gangnam Severance Hospital; Seoul; Korea