[1] Univ Hlth Network, Dept Otolaryngol Head & Neck Surg, Toronto, ON, Canada
[2] Univ Hlth Network, Div Thorac Surg, Dept Surg, Toronto, ON, Canada
[3] Chris OBrien Lifehouse, Sidney Head & Neck Canc Inst, Sydney, NSW, Australia
[4] Univ Helsinki, Dept Otorhinolaryngol Head & Neck Surg, Helsinki, Finland
[5] Helsinki Univ Hosp, Helsinki, Finland
[6] Princess Margaret Canc Ctr, Dept Stat, Toronto, ON, Canada