1. Department of Surgery, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
2. Department of Surgery, Kyung Hee University Medical Center, Kyung Hee University School of Medicine, Seoul, Korea.
3. Department of Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
4. Department of Surgery, Cheil General Hospital and Women's Healthcare Center, Dankook University College of Medicine, Seoul, Korea.
5. The Korea Central Cancer Registry, Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea.
6. Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
7. Department of Surgery, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Incheon, Korea.
8. Center for Breast Cancer, National Cancer Center, Goyang, Korea.
9. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea
10. Department of Surgery, Ewha Womans University Mokdong Hospital, Seoul, Korea.
11. Department of Surgery, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.