title: Patterns and trends in the incidence of paediatric and adult germ cell tumours in Australia, 1982-2011.
abstract: Germ cell tumour (GCT) aetiology is uncertain and comprehensive epidemiological studies of GCT incidence are few.
  
  
  
  Nationwide data on all malignant GCTs notified to Australian population-based cancer registries during 1982-2011 were obtained. Age- and sex-specific, and World age-standardised incidence rates were calculated for paediatric (0-14) and adult (15+) cases using the latest WHO subtype classification scheme. Temporal trends were examined using Joinpoint regression.
  
  
  
  There were 17,279 GCTs (552 paediatric, 16,727 adult). Age-specific incidence in males (all histologies combined) was bimodal, with peaks during infancy for most sites, and second, larger, peaks during young adulthood. Incidence of ovarian tumours peaked at age 15-19. Around half of paediatric tumours were extragonadal, whereas adult tumours were mostly gonadal. Yolk sac tumours and teratomas predominated in infants, whereas germinomas became more frequent towards adulthood. Increasing incidence trends for some adult gonadal tumours have stabilised; the trend for male extragonadal tumours is also declining.
  
  
  
  Broad similarities in the shape of age-specific incidence curves, particularly for gonadal, central nervous system, and mediastinal tumours provide epidemiological support for commonalities in aetiology among clinically disparate GCT subtypes. Differences in peak ages reflect underlying subtype-specific biological differences. Declining incidence trends for some adult gonadal tumours accords with the global transition in GCT incidence, and supports the possibility of a reduction in prevalence of shared aetiological exposures.
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Sydney, NSW, 2052, Australia. Electronic address: m.vanleeuwen@unsw.edu.au.
authors.forename: Marina T
authors.initials: MT
authors.lastname: van Leeuwen
authors.affiliation: Faculty of Medicine and Health Science, Macquarie University, Sydney, NSW, 2109, Australia.
authors.forename: Howard
authors.initials: H
authors.lastname: Gurney
authors.affiliation: Faculty of Medicine and Health Science, Macquarie University, Sydney, NSW, 2109, Australia; Douglass Hanly Moir Pathology, Macquarie Park, NSW, 2113, Australia.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Turner
authors.affiliation: Crown Princess Mary Cancer Centre, Westmead Hospital, Westmead, NSW, 2145, Australia.
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Turner
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Sallie-Anne
authors.initials: SA
authors.lastname: Pearson
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Maarit A
authors.initials: MA
authors.lastname: Laaksonen
authors.affiliation: Crown Princess Mary Cancer Centre, Westmead Hospital, Westmead, NSW, 2145, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Harnett
authors.affiliation: Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, 2170, Australia.
authors.forename: Bavanthi
authors.initials: B
authors.lastname: Balakrishnar
authors.affiliation: Crown Princess Mary Cancer Centre, Westmead Hospital, Westmead, NSW, 2145, Australia.
authors.forename: Dhanusha
authors.initials: D
authors.lastname: Sabanathan
authors.affiliation: Centre for Big Data Research in Health, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Claire M
authors.initials: CM
authors.lastname: Vajdic
mesh_terms: D000293:Adolescent; D000328:Adult; D001315:Australia; D002648:Child; D002675:Child, Preschool; D005260:Female; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000453:epidemiology* / Q000209:etiology; D055815:Young Adult
keywords: Australia; Germ cell neoplasms; Incidence; Ovarian neoplasms; Testicular neoplasms