[1] Christie NHS Fdn Trust, Canc Res UK Dept Med Oncol, Manchester, Lancs, England
[2] Univ Hosp South Manchester NHS Fdn Trust, Dept Med Oncol, Manchester, Lancs, England
[3] Christie NHS Fdn Trust, Dept Clin Oncol, Manchester, Lancs, England
[4] Univ Manchester, Manchester, Lancs, England