1 Department of Surgery, Research Institute of Clinical Medicine, Chonbuk National University Hospital, Chonbuk National University and Biomedical Research Institute, Jeonju, Korea.
2 Department of Surgery, Chosun University Hospital, Chosun University College of Medicine, Gwangju, Korea.
3 Department of Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
4 Department of Surgery, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Busan, Korea.
5 Division of Breast and Endocrine Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
6 The Korea Central Cancer Registry, Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea.