title: Parental cancer diagnosis and child mortality--a population-based cohort study in Sweden.
abstract: OBJECTIVE
  Cancer diagnosis is known to induce severe psychological stress for the diagnosed patients; however, how it affects the next-of-kin is less well documented. This study aimed to assess the impact of parental cancer on the risk of childhood death.
  
  
  METHODS
  A population-based cohort study was conducted using the Swedish national registries, including 2,871,242 children followed during the period of 1991-2009. Parental cancer diagnosis was defined as a time-varying exposure. We used Cox proportional hazards regression to calculate the hazard ratio (HR) and its corresponding 95% confidence interval (CI) as an estimate of the association between parental cancer and childhood mortality. We adjusted for attained age, sex, gestational age, mode of delivery and birth weight of the child, maternal age at child's birth, as well as educational level and socio-economic classification of the parents in the analyses.
  
  
  RESULTS
  Among 113,555 children with parental cancer, 127 deaths occurred during 561,198 person-years of follow-up. A parental cancer diagnosis was associated with an increased rate of death among children at the age of 1-18 (HR for all-cause death: 1.39; 95% CI: 1.16-1.66). For young children (aged 1-12), an increased rate was only noted for death due to cancer (HR: 2.06; 95% CI: 1.13-3.75) after parental cancer diagnosis. Among adolescents (aged 13-18), an increased rate was noted for all-cause death (HR: 1.52; 95% CI: 1.25-1.86), and for both non-cancer-related (HR: 1.43; 95% CI: 1.14-1.79) and cancer-related (HR: 2.07; 95% CI: 1.33-3.24) death in the exposed children.
  
  
  CONCLUSIONS
  Children have an increased rate of death if they have a parent diagnosed with cancer as compared to children without such experience; this association appears to be slightly stronger among adolescents.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. Electronic address: ruoqing.chen@ki.se.
authors.forename: Ruoqing
authors.initials: R
authors.lastname: Chen
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Arvid
authors.initials: A
authors.lastname: Sjölander
authors.affiliation: Center of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavík, Iceland.
authors.forename: Unnur
authors.initials: U
authors.lastname: Valdimarsdóttir
authors.affiliation: University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Varnum
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Lung and Allergy Unit, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Catarina
authors.initials: C
authors.lastname: Almqvist
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Weimin
authors.initials: W
authors.lastname: Ye
authors.affiliation: Clinical Epidemiology and Biostatistics Unit, School of Health and Medical Sciences, Örebro University and Örebro University Hospital, Örebro, Sweden.
authors.forename: Katja
authors.initials: K
authors.lastname: Fall
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Kamila
authors.initials: K
authors.lastname: Czene
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D046688:Child Mortality; D016241:Child of Impaired Parents / Q000706:statistics & numerical data*; D002675:Child, Preschool; D015331:Cohort Studies; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000453:epidemiology* / Q000523:psychology; D010290:Parents; D016016:Proportional Hazards Models; D012042:Registries; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000453:epidemiology* / Q000209:etiology; D013548:Sweden / Q000453:epidemiology
keywords: Cancer; Child of impaired parents; Cohort study; Death