[1] Univ Hosp Leuven, B-3000 Louvain, Belgium
[2] Leiden Univ, Med Ctr, Dept Clin Oncol, Leiden, Netherlands
[3] Univ Pisana, Med Oncol Unit, Azienda Osped, Pisa, Italy
[4] Hosp La Paz, Dept Oncol, Madrid, Spain
[5] Cross Canc Inst, Edmonton, AB T6G 1Z2, Canada
[6] Tallaght Hosp, Dublin, Ireland
[7] Univ Pisana, Med Oncol Unit 2, Azienda Osped, Pisa, Italy