[1] Rotterdam Canc Inst, Daniel Den Hoed Klin, Dept Med Oncol, Rotterdam, Netherlands
[2] Univ Rotterdam Hosp, Rotterdam, Netherlands
[3] Royal Marsden Hosp, Dept Med Oncol, Sutton, Surrey, England
[4] Univ Hosp Gasthuisberg, Dept Oncol, B-3000 Louvain, Belgium