[1] IKZ, Eindhoven Canc Registry, Comprehens Canc Ctr S, NL-5600 AE Eindhoven, Netherlands
[2] IKL, Maastricht Canc Registry, Comprehens Canc Ctr Limburg, Maastricht, Netherlands
[3] IKO, Canc Registry, Comprehens Canc Ctr E, Nijmegen, Netherlands
[4] IKST, Canc Registry, Comprehens Canc Ctr Stedendriehoek Twente, Enschede, Netherlands
[5] Maastricht Univ, Dept Epidemiol, Maastricht, Netherlands
[6] Univ Nijmegen, Med Ctr St Radboud, Dept Radiotherapy, Nijmegen, Netherlands
[7] Erasmus Univ, Med Ctr, Dept Epidemiol & Biostat, Rotterdam, Netherlands