1. Department of Surgery, Ajou University School of Medicine, Suwon, Korea.
2. Department of Surgery, Yeungnam University Hospital, Daegu, Korea.
3. Department of Biostatistics, Korea University College of Medicine, Seoul, Korea.
4. Department of Surgery, Korea Institute of Radiological and Medical Science, Seoul, Korea.
5. Department of Surgery, Samsung Medical Center, Seoul, Korea.
6. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
7. Department of Surgery, Pusan National University School of Medicine, Busan, Korea.
8. Department of Surgery, Cheil General Hospital & Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea.
9. Department of Surgery, Gachon University Gil Hospital, Incheon, Korea.
10. Department of Surgery, Chonnam National University Hwasun Hospital, Hwasun, Korea.
11. Department of Surgery, Chungnam National University Hospital, Daejeon, Korea.
12. Department of Surgery, Dong-A University Hospital, Busan, Korea.
13. Department of Surgery, Hallym University College of Medicine, Anyang, Korea.
14. Breast Cancer Center, Ewha Womans University Hospital, Seoul, Korea.
15. Department of Surgery, Chonbuk National University Medical School, Jeonju, Korea.
16. Department of Surgery, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
17. Department of Surgery, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
18. Department of Surgery, Kyungpook National University Medical Center, Daegu, Korea.
19. Department of Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
20. Department of Surgery, Wonkwang University Hospital, Iksan, Korea.
21. Department of Surgery, Daegu Catholic University Hospital, Daegu, Korea.
22. Department of Surgery, Yonsei University Gangnam Severance Hospital, Seoul, Korea.
23. Department of Surgery, CHA Gangnam Medical Center, Seoul, Korea.
24. Department of Surgery, Daerim St. Mary's Hospital, Seoul, Korea.
25. Department of Surgery, Dongguk University Ilsan Hospital, Goyang, Korea.
26. Department of Surgery, Keimyung University School of Medicine, Daegu, Korea.
27. Department of Surgery, Inje University Sanggye Paik Hospital, Seoul, Korea.
28. Department of Surgery, Kangbuk Samsung Hospital, Seoul, Korea.
29. Department of Surgery, Bundang Jesaeng Hospital, Seongnam, Korea.