1. Department of Breast and Endocrine Surgery, Kanagawa Cancer Center, Yokohama, Kanagawa 241‑8515, Japan
2. Department of Surgery, Hiratsuka Kyosai Hospital, Hiratsuka, Kanagawa 254‑8502, Japan
3. Departments of Breast and Thyroid Surgery, Yokohama City University Medical Center, Yokohama, Kanagawa 232‑0024, Japan