[1] Royal Marsden Hosp, Dept Med, Sutton, Surrey, England
[2] Sunnybrook Hlth Sci Ctr, Div Haematol Med Oncol, Toronto, ON M4N 3M5, Canada
[3] HELIOS Klin, Robert Rossle Klin, Charite, Berlin, Germany
[4] Peter MacCallum Canc Inst, Melbourne, Vic 3000, Australia
[5] Ist Nazl Tumori, Div Med Oncol, Unit 2, I-20133 Milan, Italy
[6] Paraxel, Dept Stat, Paris, France
[7] F Hoffmann La Roche & Co Ltd, CH-4002 Basel, Switzerland
[8] Univ Hosp Gasthuisberg, Digest Oncol Unit, B-3000 Louvain, Belgium