title: Radiation-induced sarcoma: 25-year experience from the Norwegian Radium Hospital.
abstract: BACKGROUND
  The aim of this study was to determine the prevalence and outcome of radiation-induced sarcomas (RISs) among sarcoma patients referred to the Norwegian Radium Hospital (NRH).
  
  
  METHODS
  Ninety patients were identified from the institutional sarcoma data base. Medical records and histological and cytological material from both primary and secondary tumours were reviewed.
  
  
  RESULTS
  RIS represented 3.0 % of the sarcomas in the data base. The median latency time from radiotherapy of the primary tumour to the diagnosis of RIS was 13.6 years (range 2.5-57.8 years). Gynaecological, breast and testicular cancers were the most common primary diagnoses. For the RISs 13 different histological types were identified including 25 malignant fibrous histiocytomas (28% of all) and 22 osteosarcomas (24%). The sarcoma-related 5-year crude survival was 33% (95 % CI 23-43 %). Unfavourable prognostic factors were metastases at presentation, incomplete surgery and presence of tumour necrosis.
  
  
  CONCLUSIONS
  Radiation-induced sarcoma is rare and harbours an aggressive clinical behaviour. Complete surgical resection is mandatory for cure.
authors.affiliation: Division of Pathology, Norwegian Radium Hospital, Rikshospitalet University Hospital, Oslo, Norway. bodil.bjerkehagen@radiumhospitalet.no
authors.forename: Bodil
authors.initials: B
authors.lastname: Bjerkehagen
authors.forename: Sigbjørn
authors.initials: S
authors.lastname: Smeland
authors.forename: Lise
authors.initials: L
authors.lastname: Walberg
authors.forename: Sigmund
authors.initials: S
authors.lastname: Skjeldal
authors.forename: Kirsten Sundby
authors.initials: KS
authors.lastname: Hall
authors.forename: Jahn M
authors.initials: JM
authors.lastname: Nesland
authors.forename: Milada Cvancarova
authors.initials: MC
authors.lastname: Småstuen
authors.forename: Sophie D
authors.initials: SD
authors.lastname: Fosså
authors.forename: Gunnar
authors.initials: G
authors.lastname: Saeter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009369:Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D009664:Norway / Q000453:epidemiology; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D012509:Sarcoma / Q000453:epidemiology* / Q000556:secondary; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult