[1] Singleton Hosp, South West Wales Canc Ctr, Sketty Lane, Swansea SA2 8QA, Wales
[2] Swansea Univ, Med Sch, Grove Bldg, Singleton Pk, Swansea SA2 8PP, Wales
[3] Imperial Coll London, St Marys Hosp, Dept Surg & Canc, Praed St, London W2 1NY, England
[4] Cardiff Univ, Ctr Trials Res, Velindre Rd, Whitchurch CF14 2TL, England
[5] Velindre Canc Ctr, Velindre Rd, Whitchurch CF14 2TL, England