1. Department of Otolaryngology–Head and Neck Surgery, University of Washington, Seattle, Washington, USA
2. Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
3. Department of Otolaryngology–Head and Neck Surgery, University of Minnesota, Minneapolis, Minnesota, USA
4. Program in Epidemiology, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
5. Department of Pathology, University of Washington, Seattle, Washington, USA
6. Department of Epidemiology, University of Washington, Seattle, Washington, USA