title: Childhood cancer and social contact: the role of paternal occupation (United Kingdom).
abstract: OBJECTIVE
  To investigate the relationship between childhood cancer (particularly leukaemia) and paternal occupational social contact (a proxy for potential exposure to infections) using the UK Childhood Cancer Study.
  
  
  METHODS
  Using a national population-based case-control study, self-reported occupational data from fathers of 3596 children diagnosed with cancer between 1991 and 1996 under 15 years of age (cases) and fathers of 7011 children without cancer (controls) were analysed. Associations were assessed using odds ratios (OR) calculated by time of exposure (birth, diagnosis), diagnostic group (all cancers, leukaemia, acute lymphoblastic leukaemia (ALL), central nervous system tumours, other cancers), level of occupational social contact (high, medium, low), urban-rural status at diagnosis and occupational title.
  
  
  RESULTS
  From 371 occupations, 75 (20%) were classified as having high levels of occupational social contact, 31 (8%) as medium and the remaining 265 (71%) as low. No associations were apparent for fathers' occupational social contact overall, for any time period or diagnostic group. OR for leukaemia and high levels of paternal occupational social contact at birth and diagnosis being 1.02 (95% confidence interval (CI) = 0.88-1.18) and 0.91 (95% CI = 0.79-1.06), respectively. Analyses by urban-rural status at diagnosis and by occupational title revealed no notable associations.
  
  
  CONCLUSIONS
  The analyses of paternal occupational histories do not support the suggested association between high levels of paternal occupational social contact and an increased risk of childhood leukaemia. However, the role of participation bias should not be discounted.
authors.affiliation: Academic Centre for Defence Mental Health, Institute of Psychiatry, King's College London, Weston Education Centre, Cutcombe Road, London SE5 9RJ , UK. Nicola.Fear@iop.kcl.ac.uk
authors.forename: Nicola T
authors.initials: NT
authors.lastname: Fear
authors.forename: Jill
authors.initials: J
authors.lastname: Simpson
authors.forename: Eve
authors.initials: E
authors.lastname: Roman
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005220:Fathers; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007398:Interpersonal Relations; D008297:Male; D009369:Neoplasms / Q000453:epidemiology*; D016273:Occupational Exposure / Q000032:analysis; D009790:Occupations / Q000145:classification*; D018570:Risk Assessment; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology