title: The incidences of malignant gonadal and extragonadal germ cell tumors in males and females: a population-based study covering over 40 years in Finland.
abstract: OBJECTIVE
  Germ cell tumors (GCTs) comprise a heterogeneous group of tumors derived from primordial germ cells. The incidence of malignant testicular GCTs has increased in recent decades, but little is known about possible changes in malignant female GCTs. Population-based data covering all malignant GCTs in both sexes remain limited.
  
  
  METHODS
  All cases of malignant GCTs in 1969-2008 were collected from the Finnish Cancer Registry and their age-adjusted annual incidences calculated.
  
  
  RESULTS
  The overall incidence of malignant GCTs was 2.56 per 100,000 person-years in males and 0.34 per 100,000 in females. The incidence of gonadal GCTs increased from 2.27 to 8.36 per 100,000 in males between 15 and 44 years of age. Moreover, the incidence of all histological subtypes of gonadal GCTs increased in males. In females, the only increase was seen in the incidence of ovarian non-dysgerminoma (from 0.07 to 0.29/100,000). The incidence of extragonadal GCTs did not change during the study period, being 0.18 and 0.10 per 100,000 in males and females, respectively.
  
  
  CONCLUSIONS
  The incidence of gonadal GCTs in males increased significantly during the 40-year study period, whereas in females, no such change was observed. There were significant gender differences regarding the distribution of histological subtypes and patients' ages. However, the incidence of extragonadal GCTs remained low in both sexes. The differences in the incidences of gonadal GCTs derived from the same population suggest that the risk factors of these malignancies differ between the two sexes.
authors.affiliation: Paediatric Research Centre, University of Tampere and Tampere University Hospital, Medical School, 33014, Tampere, Finland.
authors.forename: Satu-Liisa
authors.initials: SL
authors.lastname: Pauniaho
authors.forename: Jonna
authors.initials: J
authors.lastname: Salonen
authors.forename: Mika
authors.initials: M
authors.lastname: Helminen
authors.forename: Kim
authors.initials: K
authors.lastname: Vettenranta
authors.forename: Markku
authors.initials: M
authors.lastname: Heikinheimo
authors.forename: Oskari
authors.initials: O
authors.lastname: Heikinheimo
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005387:Finland; D006801:Humans; D015994:Incidence; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000453:epidemiology*; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D013736:Testicular Neoplasms / Q000453:epidemiology*; D055815:Young Adult