[1] Canc Registry Norway, POB 5313, N-0304 Oslo, Norway
[2] Univ Oslo, Inst Hlth & Soc, Oslo, Norway
[3] Univ Tromso, Arctic Univ Norway, Dept Community Med, Fac Hlth Sci, Tromso, Norway
[4] Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden
[5] Folkhalsan Res Ctr, Genet Epidemiol Grp, Helsinki, Finland
[6] Oncol Inst Prof Dr Ion Chiricuta Cluj Napoca, Cluj Napoca, Romania
[7] Univ Med & Pharm, Iuliu Hatieganu, Cluj Napoca, Romania
[8] Univ Oslo, Inst Basic Med Sci, Oslo, Norway