1. Department of Surgery and Cancer Research Institute, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
2. Department of Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
3. Department of Surgery, National Cancer Centre, Goyang, Korea
4. Department of Surgery, Ajou University Hospital, Suwon, Korea
5. Department of Surgery, Yonsei University Severance Hospital, Seoul, Korea
6. Department of Surgery, Gyeongsang National University Hospital, Daegu, Korea
7. Department of Surgery, Kyungpook National University Hospital, Daegu, Korea
8. Department of Surgery, Yeouido St. Mary’s Hospital, The Catholic University of Korea, Seoul, Korea
9. Department of Surgery, Chonnam National University Medical School, Hwasun, Korea