1. Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland
2. Department of Otorhinolaryngology – Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
3. Research Program in Systems Oncology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
4. Unit of Health Sciences, Faculty of Social Sciences, Tampere University, Tampere, Finland
5. Department of Public Health, University of Helsinki, Helsinki, Finland
6. Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet and Karolinska Hospital, Stockholm, Sweden