1. KU Leuven University Herestraat 49 Leuven 3000 Belgium
2. Belgian Cancer Registry (BCR) Koningsstraat 215 Brussels 1210 Belgium
3. Netherlands Comprehensive Cancer Organisation (IKNL) Godebaldkwartier 419 Utrecht 3511 DT The Netherlands
4. University Hospital Ghent Corneel Heymanslaan 10 Gent 9000 Belgium
5. Leiden University Medical Centre (LUMC) Albinusdreef 2 Leiden 2333 ZA The Netherlands