1. Division of Gastrointestinal Oncology, Shizuoka Cancer Center, Sunto-gun, Japan
2. Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
3. Department of Medical Oncology and Hematology, Kobe University Hospital, Kobe, Japan
4. Department of Head and Neck Medical Oncology, National Cancer Center Hospital East, Kashiwa, Japan
5. Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Nagoya, Japan
6. Department of Head and Neck Surgery, Tokyo Medical and Dental University, Tokyo, Japan
7. Department of Head and Neck Surgery, National Cancer Center Hospital East, Kashiwa, Japan
8. Department of Otolaryngology-Head and Neck Surgery, Tohoku University Hospital, Sendai, Japan
9. Department of Otolaryngology and Head and Neck Surgery, University of Tokyo, Tokyo, Japan
10. Department of Otorhinolaryngology, Head and Neck Surgery, Yokohama City University School of Medicine, Yokohama, Japan
11. Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan
12. Department of Radiation Oncology, National Cancer Center Hospital East, Kashiwa, Japan
13. Department of Radiation Oncology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
14. Department of Medical Oncology, Cancer Institute Hospital, Tokyo, Japan
15. Department of Medical Oncology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
16. Department of Medical Oncology, Hyogo Cancer Center, Akashi, Japan