1. Department of Breast Oncology Miyagi Cancer Center Natori Japan
2. Department of Healthcare Quality Assessment Graduate School of Medicine The University of Tokyo Tokyo Japan
3. Departments of Breast and Endocrine Surgery Okayama University Hospital Okayama Japan
4. Departments of Breast and Endocrine Surgery Tokai University School of Medicine Isehara Japan
5. Department of Surgery Kitakyushu Municipal Medical Center Kitakyushu Japan
6. Department of Breast Surgery St. Luke's International Hospital Tokyo Japan
7. Department of Breast Surgery Shikoku Cancer Center Matsuyama Japan
8. Department of Surgical Oncology Graduate School of Medicine Tohoku University Sendai Japan
9. Sapporo‐kotoni Breast Clinic Sapporo Japan
10. Department of Breast Oncology Cancer Institute Hospital Tokyo Japan
11. Department of Pathology Nihon University School of Medicine Tokyo Japan
12. Division of Breast and Endocrine Surgery Department of Surgery St. Marianna University School of Medicine Kawasaki Japan
13. Department of Breast Surgery National Cancer Center Hospital Tokyo Japan
14. Division of Breast Surgical Oncology Department of Surgery Showa University Tokyo Japan