*Departments of Otorhinolaryngology, Head and Neck Surgery, University of Turku, Finland
†Department of Pathology, University of Turku, Finland
‡Haartman Institute, Department of Pathology, University of Helsinki, Helsinki University Central Hospital, Finland
§Department of Otolaryngology, University of Oulu, Finland
¶Department of Otorhinolaryngology, Head and Neck Surgery, University of Tampere, Finland
**Department of Otolaryngology, Head and Neck Surgery, Helsinki University Central Hospital, Finland
††Department of Otorhinolaryngology, Head and Neck Surgery, Kuopio University Hospital, Finland
‡‡Department of Biostatistics, University of Turku, Finland
