[1] Univ Bern, Inst Social & Prevent Med, Childhood Canc Res Grp, Bern, Switzerland
[2] Univ Bern, Grad Sch Hlth Sci, Bern, Switzerland
[3] Univ Hosp Geneva, Dept Paediat Obstet & Gynaecol, Div Paediat Haematol & Oncol, Geneva, Switzerland
[4] Univ Ctr Dent Med Basel UZB, Dept Children & Adolescent Dent, Basel, Switzerland
[5] Univ Childrens Hosp Basel UKBB, Dept Oncol Haematol, Basel, Switzerland
[6] Childhood Canc Switzerland, Basel, Switzerland
[7] Univ Bern, Bern Univ Hosp, Inselspital, Dept Paediat, Bern, Switzerland