[1] Royal Hallamshire Hosp, Dept Haematol, Sheffield S10 2JF, S Yorkshire, England
[2] Royal Hallamshire Hosp, Inst Canc Studies, Sheffield S10 2JF, S Yorkshire, England
[3] Royal Hallamshire Hosp, Dept Pathol, Sheffield S10 2JF, S Yorkshire, England
[4] Weston Pk Hosp, Yorkshire Canc Res Dept Clin Oncol, Sheffield, S Yorkshire, England