1. Department of Breast and Medical Oncology, National Center for Global Health and Medicine, Tokyo, Japan
2. Department of Medical Oncology, Shimane University Hospital, Shimane, Japan
3. Department of Breast and Endocrine Surgery, Toranomon Hospital, Tokyo, Japan
4. Department of Medical Oncology, Kyorin University Faculty of Medicine, Tokyo, Japan
5. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan
6. Department of Breast Oncology, Aichi Cancer Center Hospital, Aichi, Japan
7. Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama Japan