[1] Univ Hosp Geneva, Dept Oncosurg, Oncosurg Unit, CH-1211 Geneva 14, Switzerland
[2] Univ Lausanne Hosp, Multidisciplinary Oncol Ctr, Lausanne, Switzerland
[3] Inselspital Bern, Swiss Grp Clin Canc Res Coordinating Ctr, Dept Med Oncol, Bern, Switzerland
[4] Osped Civico, Inst Oncol So Switzerland, Lugano, Switzerland
[5] Kantonsspital, Dept Med C, Div Oncol, St Gallen, Switzerland
[6] Kantonsspital Aarau, Aarau, Switzerland
[7] Triemli Municipal Hosp, Inst Med Oncol, Zurich, Switzerland
[8] European Inst Oncol, Dept Med, Milan, Italy
[9] Bristol Oncol Ctr, Bristol, Avon, England
[10] St Thomas Hosp, London, England
[11] Mt Vernon Hosp, Middlesex, England
[12] Cookridge Hosp, Leeds LS16 6QB, W Yorkshire, England