Division of Breast Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea, Department of Surgery, Konkuk Universitiy Medical Center, Seoul, South Korea, Department of Surgery, University of Ulsan College of Medicine and ASAN Medical Center, Seoul, South Korea, Department of Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea, Division of Breast Surgery, Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea, Division of Breast Surgery, Department of Surgery, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea, Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, South Korea, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine, Seoul, South Korea, Department of Surgery, Ajou University, School of Medicine, Suwon, South Korea, Department of Surgery, Chonnam National University Medical School & Chonnam National University Hwasun Hospital, Gwangju, South Korea, Korea University Anam Hospital, Department of internal medicine, Division of Medical oncology/Hematology, Seoul, South Korea, Yeungnam University College of Medicine, Daegu, South Korea, Division of Breast Surgery, Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea, Dong-A University Hospital, Dong-A University College of Medicine, Busan, South Korea, Department of Surgery, Soonchunhyang University Cheonan Hospital, Cheonan, South Korea, Soonchunhyang University Hospital, Seoul, South Korea, Division of Breast and Endocrine Surgery, Hallym University Sacred Heart Hospital, Anyang, South Korea, Ewha Womans University College of Medicine, Seoul, South Korea, Department of Clinical Epidemiology and Biostatistics, Asan Medical Center, Seoul, South Korea, Division of Breast, Department of Surgery, College of Medicine, University of Ulsan, Seoul, South Korea