[1] Sci Inst Publ Hlth, Belgian Canc Ctr, Canc Epidemiol Unit, B-1050 Brussels, Belgium
[2] Canc Registry Norway, Oslo, Norway
[3] Folkhalsan Res Ctr, Dept Genet Epidemiol, Helsinki, Finland
[4] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden
[5] Univ Tromso, Inst Community Med, Tromso, Norway
[6] Univ Oslo, Inst Basic Med Sci, Oslo, Norway
[7] Finnish Canc Registry, FIN-00170 Helsinki, Finland