1. Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
2. Department of Otolaryngology-Head and Neck Surgery, China-Japan Friendship Hospital, Beijing 100029, China
3. Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
4. Department of Otolaryngology-Head and Neck Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
5. Duke Cancer Institute, Duke University Medical Center, Durham, NC 27710, USA