title: Childhood exposures among mothers and Hodgkin's lymphoma in offspring.
abstract: BACKGROUND
  Childhood exposures in mothers, signaled by number of older and younger siblings, have lifelong consequences for aspects of immune function. We hypothesized that these may influence young adult-onset Hodgkin's lymphoma (HL) risk in offspring.
  
  
  METHODS
  Swedish registers identified 2028 cases of young adult onset HL (diagnosed between ages 15-39 years) up to 2012 among those born since 1958; and 18,374 matched controls. Conditional logistic regression was used to assess HL risk associated with number of older and younger siblings of mothers.
  
  
  RESULTS
  Having a mother with more than two older siblings is associated with lower HL risk, and the association is statistically significant for mothers with three or more siblings, compared with none. The adjusted odds ratios (and 95% confidence intervals) are 1.04 (0.93-1.16); 0.95 (0.81-1.10); and 0.81 (0.66-0.98) for one, two, and three or more older siblings, respectively. There is no association between number of mothers' younger siblings and HL risk.
  
  
  CONCLUSIONS
  Exposures during the childhood of mothers may influence young onset adult HL risk in offspring, perhaps through vertical transmission of infectious agents, or through other long-term influences on maternal immune function.
authors.affiliation: Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University, Örebro SE-701 82, Sweden; Department of Epidemiology and Public Health, University College London WC1E 6BT, UK; Clinical Epidemiology Unit, Department of Medicine, Karolinska University Hospital, Karolinska Institutet, Stockholm SE-171 76, Sweden. Electronic address: scott.montgomery@oru.se.
authors.forename: Scott
authors.initials: S
authors.lastname: Montgomery
authors.affiliation: Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University, Örebro SE-701 82, Sweden.
authors.forename: Ole
authors.initials: O
authors.lastname: Brus
authors.affiliation: Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University, Örebro SE-701 82, Sweden.
authors.forename: Ayako
authors.initials: A
authors.lastname: Hiyoshi
authors.affiliation: Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University, Örebro SE-701 82, Sweden; Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm SE-171 77, Sweden.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston 02115, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rider
authors.affiliation: Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University, Örebro SE-701 82, Sweden; Clinical Epidemiology Unit, Department of Medicine, Karolinska University Hospital, Karolinska Institutet, Stockholm SE-171 76, Sweden.
authors.forename: Katja
authors.initials: K
authors.lastname: Fall
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006689:Hodgkin Disease / Q000453:epidemiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D009035:Mothers / Q000706:statistics & numerical data*; D016017:Odds Ratio; D055815:Young Adult
keywords: Case-control; Hodgkin’s lymphoma; Intergenerational relations; Mother; Siblings