[1] Univ Liverpool, Sch Hlth Sci, Liverpool Head & Neck Ctr, Liverpool, Merseyside, England
[2] Newcastle Univ, Newcastle Univ Ctr Canc, Populat Hlth Sci Inst, Newcastle Upon Tyne, Tyne & Wear, England
[3] South Tyneside & Sunderland NHS Fdn Trust, London, England
[4] Southmead Hosp North Bristol NHS Hosp Trust, Bristol Speech & Language Therapy Res Unit, Bristol BS10 5NB, Avon, England
[5] Univ Hosp Bristol, NIHR Bristol Biomed Res Ctr, Bristol BS2 8AE, Avon, England
[6] German Canc Res Ctr, Infect & Canc Epidemiol, Heidelberg, Germany