title: Survival From Childhood Hematological Malignancies in Denmark: Is Survival Related to Family Characteristics?
abstract: BACKGROUND
  Due to diverse findings as to the role of family factors for childhood cancer survival even within Europe, we explored a nationwide, register-based cohort of Danish children with hematological malignancies.
  
  
  METHODS
  All children born between 1973 and 2006 and diagnosed with a hematological malignancy before the age of 20 years (N = 1,819) were followed until 10 years from diagnosis. Kaplan-Meier curves and Cox proportional hazards models estimating hazard ratios (HR) and 95% confidence intervals (CI) were used to assess the impact of family characteristics on overall survival in children with hematological malignancies.
  
  
  RESULTS
  Having siblings and increasing birth order were associated with reduced survival from acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Associations with AML were strongest and statistically significant. HRs of 1.62 (CI 0.85; 3.09) and 5.76 (CI 2.01; 16.51) were observed for the fourth or later born children with ALL (N = 41) and AML (N = 9), respectively. Children with older parents showed a tendency toward inferior ALL survival, while for AML young maternal age was related to poorer survival. Based on small numbers, a trend toward poorer survival from non-Hodgkin lymphoma was observed for children having siblings and for children of younger parents.
  
  
  CONCLUSIONS
  Further research is warranted to gain further knowledge on the impact of family factors on childhood cancer survival in other populations and to elaborate potential underlying mechanisms and pathways of those survival inequalities.
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer (IARC), Lyon, France.
authors.forename: Friederike
authors.initials: F
authors.lastname: Erdmann
authors.affiliation: Survivorship Unit, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Jeanette Falck
authors.initials: JF
authors.lastname: Winther
authors.affiliation: Survivorship Unit, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Susanne Oksbjerg
authors.initials: SO
authors.lastname: Dalton
authors.affiliation: Epidemiology & Cancer Statistics Group, Department of Health Sciences, University of York, Heslington, York, UK.
authors.forename: Tracy
authors.initials: T
authors.lastname: Lightfoot
authors.affiliation: Department of Prevention and Evaluation, Leibniz Institute for Prevention Research and Epidemiology BIPS GmbH, Bremen, Germany.
authors.forename: Hajo
authors.initials: H
authors.lastname: Zeeb
authors.affiliation: Survivorship Unit, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Sofie Bay
authors.initials: SB
authors.lastname: Simony
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer (IARC), Lyon, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Deltour
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer (IARC), Lyon, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Ferro
authors.affiliation: Survivorship Unit, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bautz
authors.affiliation: Department of Pediatrics & Adolescent Medicine, University Hospital Rigshospitalet, Copenhagen, Denmark.|Division of Pediatric Hematology/Oncology, Perlmutter Cancer Center, New York University Langone Medical Center, New York, New York.
authors.forename: Kjeld
authors.initials: K
authors.lastname: Schmiegelow
authors.affiliation: Section of Environment and Radiation, International Agency for Research on Cancer (IARC), Lyon, France.
authors.forename: Joachim
authors.initials: J
authors.lastname: Schüz
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005191:Family Characteristics; D005260:Female; D019337:Hematologic Neoplasms / Q000401:mortality*; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D010331:Paternal Age; D016016:Proportional Hazards Models; D012042:Registries; D055815:Young Adult
keywords: acute lymphoblastic leukemia; acute myeloid leukemia; childhood hematological malignancies; family characteristics; lymphoma; survival