[1] Erasmus MC Univ Med Ctr Rotterdam, Rotterdam, Netherlands
[2] EORTC Data Ctr, Dept Biostat, Brussels, Belgium
[3] European Inst Oncol, Milan, Italy
[4] Natl Canc Inst, I-20133 Milan, Italy
[5] Univ Med Ctr Nijmegen, Nijmegen, Netherlands
[6] Inst Jules Bordet, B-1000 Brussels, Belgium
[7] St James Univ Hosp, Canc Res UK Clin Ctr, Leeds, W Yorkshire, England
[8] Inst Gustave Roussy, Villejuif, France