[1] Erasmus Univ, Ctr Med, Rotterdam, Netherlands
[2] Eortc Data Ctr, Brussels, Belgium
[3] Natl Canc Inst, I-20133 Milan, Italy
[4] European Canc Inst, Milan, Italy
[5] Univ Birmingham, Birmingham, W Midlands, England
[6] Univ Nijmegen, Ctr Med, Nijmegen, Netherlands
[7] Univ Kiel, Kiel, Germany
[8] Royal Marsden Hosp, London SW3 6JJ, England
[9] Charite Univ Med Berlin, Berlin, Germany