title: Perinatal risk factors for childhood testicular germ-cell cancer: a Nordic population-based study.
abstract: BACKGROUND
  In contrast to research in adults, there have been limited studies on testicular germ-cell cancer among boys aged <15 years. The aim of the study was to investigate the association between perinatal characteristics and childhood testicular germ-cell cancer.
  
  
  METHODS
  We identified 152 patients with childhood germ-cell cancer among boys (<15 years) born in Norway, Sweden, Finland and Denmark between 1967 and 2006 using the cancer and medical birth registries. For each case we sampled 10 population controls matched on year and country of birth. We used conditional logistic regression analysis to estimate odds ratios for cancer risk.
  
  
  RESULTS
  There was a weak, positive association between high (≥4000 g) birth weight and childhood testicular germ-cell cancer (adjusted OR=1.25; 95% CI: 0.83-1.90) compared with normal birth weight, and a correspondingly elevated risk for low birth weight (adjusted OR=1.41; 95% CI: 0.43-4.56). For Ponderal Index (PI) there was an increased risk for low and high values compared to those in the middle category (adjusted OR=1.64; 95% CI: 1.03-2.62 and 1.67; 95% CI: 0.93-2.99), respectively. There was no association between birth length and childhood testicular germ-cell cancer. The adjusted OR for testicular cancer among first born was 1.40; 95% CI: 0.96-2.05. Greater maternal age and less maternal education appeared to increase the risk, but the estimates were not statistically significant.
  
  
  CONCLUSIONS
  We found a U-shaped association between fetal growth, measured as the PI, and childhood testicular germ-cell cancer. Our findings support the notion that abnormal fetal growth rate confers a risk in pediatric testicular cancer [corrected].
authors.affiliation: Clinical Epidemiology Unit and Centre for Pharmacoepidemiology, Department of Medicine, Karolinska University Hospital and Institute, Stockholm, Sweden. olof.stephansson@ki.se
authors.forename: Olof
authors.initials: O
authors.lastname: Stephansson
authors.forename: Caroline
authors.initials: C
authors.lastname: Wahnström
authors.forename: Andreas
authors.initials: A
authors.lastname: Pettersson
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
authors.forename: Steinar
authors.initials: S
authors.lastname: Tretli
authors.forename: Mika
authors.initials: M
authors.lastname: Gissler
authors.forename: Rebecca
authors.initials: R
authors.lastname: Troisi
authors.forename: Olof
authors.initials: O
authors.lastname: Akre
authors.forename: Tom
authors.initials: T
authors.lastname: Grotmol
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001722:Birth Order; D001724:Birth Weight; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000453:epidemiology*; D009664:Norway / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D013736:Testicular Neoplasms / Q000453:epidemiology*