title: UK case control study of brain tumours in children, teenagers and young adults: a pilot study.
abstract: BACKGROUND
  Tumours of the central nervous system are the second most common group of childhood cancers in 0-14 year olds (24% of total cancers) and represent a major diagnostic group in 15-24 year olds. The pilot case-control study aimed to establish methodologies for a future comprehensive aetiological investigation among children and young adults.
  
  
  METHODS
  Eligible cases were newly diagnosed with an intracranial tumour of neuroepithelial tissue aged 0-24 years. The pilot recruited patients through Leeds and Manchester Principal Treatment Centres. Controls were drawn from general practice lists. Controls were frequency matched by age and gender.
  
  
  RESULTS
  We interviewed 49 cases and 78 controls comprising 85% of the target sample size. Response rates were 52% for cases and 32% for controls. Completion of the questionnaire was successful, with a very small proportion of missing data being reported (5-10%). The age distribution of cases and controls was similar with around three-quarters of interviewed subjects aged 0-14. Half of cases and almost two-thirds of controls reported using a mobile phone with the majority starting between 10-14 years of age. Prevalence of breastfeeding was lower in cases than controls (Odds Ratio 0.4; 95% CI 0.2-1.2), whilst cases were more likely to be delivered by caesarean section (OR 1.6; 95% CI 0.6-4.4). Cases were significantly more likely to have a birthweight > 3.5 kg compared to controls. Cases were also more likely to come from a family with 3 or more siblings than controls (OR 3.0; 95% CI 0.7-13.6). The majority of participants (>80%) were in favour of taking either blood or saliva to aid molecular epidemiological research.
  
  
  CONCLUSIONS
  Successful methods were established for identifying and recruiting a high proportion of case subjects, exploiting strong links with the clinical teams at the treatment centres. Control procedures proved more difficult to implement. However, working closely with national clinical and professional research networks will enable improved control identification and recruitment, with good prospects for collecting biological samples in the future.
authors.affiliation: Division of Epidemiology and Biostatistics, School of Medicine, University of Leeds, Leeds LS2 9JT, UK. r.g.feltbower@leeds.ac.uk.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Feltbower
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Fleming
authors.forename: Susan V
authors.initials: SV
authors.lastname: Picton
authors.forename: Robert D
authors.initials: RD
authors.lastname: Alston
authors.forename: Diana
authors.initials: D
authors.lastname: Morgan
authors.forename: Janice
authors.initials: J
authors.lastname: Achilles
authors.forename: Patricia A
authors.initials: PA
authors.lastname: McKinney
authors.forename: Jillian M
authors.initials: JM
authors.lastname: Birch
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D001254:Astrocytoma / Q000453:epidemiology*; D015982:Bias; D001932:Brain Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004806:Ependymoma / Q000453:epidemiology*; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000453:epidemiology*; D010865:Pilot Projects; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult