title: Epidemiological study of paediatric germ cell tumours revealed the incidence and distribution that was expected, but a low mortality rate.
abstract: OBJECTIVE
  Germ cell tumours (GCTs) are a rare heterogeneous tumour group derived from primordial germ cells, which can be benign or malignant and occur in the gonads or extragonadally. This study mapped the paediatric GCTs in Denmark from 1984 to 2013 to study the incidence and outcome.
  
  
  METHODS
  We identified paediatric GCTs from the Danish Childhood Cancer and National Pathology Registries and reviewed the case records for patient characteristics, tumour characteristics and clinical outcome.
  
  
  RESULTS
  We identified 403 (71% female) paediatric GCTs and the crude incidence was 1.43 per 100 000. Of these, 79 (20%) were malignant, 39 (10%) were potentially malignant and 285 (70%) were benign. Extragonadal GCTs (39%) were mainly observed in early childhood and were predominately sacrococcygeal teratomas. Gonadal GCTs (61%) in late childhood were most frequently mature teratomas in the ovaries. Nearly all patients underwent surgery. Of the malignant tumours, 62% were treated with chemotherapy. Radiotherapy was only administered to intracranial GCTs. In the cohort, 12 patients died (3%).
  
  
  CONCLUSIONS
  Paediatric GCTs in Denmark were mainly benign and mortality was low, even for malignant tumours. We identified a peak of extragonadal GCTs in early childhood and a peak of gonadal GCTs in late childhood, which was comparable to previous reports.
authors.affiliation: Department of Paediatric and Adolescent Haematology and Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Madeline
authors.initials: M
authors.lastname: Evers
authors.affiliation: Department of Paediatric and Adolescent Haematology and Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Catherine
authors.initials: C
authors.lastname: Rechnitzer
authors.affiliation: Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Graem
authors.affiliation: Department of Paediatric Haematology and Oncology, H. C. Andersen Children's Hospital, Odense University Hospital, Odense, Denmark.
authors.forename: Peder
authors.initials: P
authors.lastname: Skov Wehner
authors.affiliation: Department of Paediatric Oncology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Schroeder
authors.affiliation: Paediatric Oncology Section, Paediatric Department, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Rosthoej
authors.affiliation: Department of Growth and Reproduction, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Christiane Hammershaimb
authors.initials: CH
authors.lastname: Mosbech
authors.affiliation: Department of Paediatrics, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Christina Engel
authors.initials: CE
authors.lastname: Hoei-Hansen
authors.affiliation: Department of Paediatric and Adolescent Haematology and Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Astrid
authors.initials: A
authors.lastname: Sehested
authors.affiliation: Cancer Section, Institute of Child Health, University College London, London, UK.
authors.forename: Taryn D
authors.initials: TD
authors.lastname: Treger
authors.affiliation: Department of Paediatric and Adolescent Haematology and Oncology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.|Cancer Section, Institute of Child Health, University College London, London, UK.
authors.forename: Jesper
authors.initials: J
authors.lastname: Brok
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D004701:Endocrine Gland Neoplasms / Q000401:mortality* / Q000628:therapy; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000401:mortality* / Q000628:therapy
keywords: Denmark; Epidemiology; Germ cell tumours; Incidence; Mortality