title: Osteosarcoma of the pelvis.
abstract: OBJECTIVE
  Osteosarcoma of the pelvis is a particularly difficult tumour to treat as it often presents late, may be of considerable size and/or associated with metastases when it presents, and is frequently chondroid in origin and resistant to chemotherapy. The aim of this study was to review our experience of managing this group of patients and to identify features predictive of a poor outcome.
  
  
  METHODS
  Between 1983 and 2014, 121 patients, (74 females and 47 males) were treated at a single hospital: 74 (61.2%) patients had a primary osteosarcoma and 47 (38.8%) had an osteosarcoma which was secondary either to Paget's disease (22; 18.2%) or to previous pelvic irradiation (25; 20.7%). The mean age of those with a primary osteosarcoma was 29.3 years (nine to 76) and their mean follow-up 2.9 years (0 to 29). The mean age of those with a secondary sarcoma was 61.9 years (15 to 85) and their mean follow-up was one year (0 to 14). A total of 22 patients with a primary sarcoma (52.4%) and 20 of those with a secondary sarcoma (47.6%) had metastases at the time of presentation.
  
  
  RESULTS
  The disease-specific survival at five years for all patients was 27.2%. For those without metastases at the time of diagnosis, the five-year survival was 32.7%. Factors associated with a poor outcome were metastases at diagnosis and secondary tumours. In primary osteosarcoma, sacral location, surgical margin and a diameter > 10 cm were associated with a poor outcome.
  
  
  CONCLUSIONS
  In this, the largest single series of patients with an osteosarcoma of the pelvis treated in a single hospital, those with secondary tumours and those with metastases at presentation had a particularly poor outcome. For those with a primary sarcoma, sacral location, an intralesional margin and a diameter of > 10 cm were poor prognostic indicators.
authors.affiliation: The Royal Orthopaedic Hospital, Bristol Road South, Birmingham, B31 2AP, UK.
authors.forename: M C
authors.initials: MC
authors.lastname: Parry
authors.affiliation: Tampere University Hospital, Tampere, Finland and, Oncology Unit, Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Laitinen
authors.affiliation: Hospital Italiano Buenos Aires, Buenos Aires, Argentina and, Oncology Unit, Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, UK.
authors.forename: J
authors.initials: J
authors.lastname: Albergo
authors.affiliation: The Royal Orthopaedic Hospital, Bristol Road South, Birmingham, B31 2AP, UK.
authors.forename: L
authors.initials: L
authors.lastname: Jeys
authors.affiliation: The Royal Orthopaedic Hospital, Bristol Road South, Birmingham, B31 2AP, UK.
authors.forename: S
authors.initials: S
authors.lastname: Carter
authors.affiliation: The Royal Orthopaedic Hospital, Bristol Road South, Birmingham, B31 2AP, UK.
authors.forename: C L
authors.initials: CL
authors.lastname: Gaston
authors.affiliation: The Royal Orthopaedic Hospital, Bristol Road South, Birmingham, B31 2AP, UK.
authors.forename: V
authors.initials: V
authors.lastname: Sumathi
authors.affiliation: The Royal Orthopaedic Hospital, Bristol Road South, Birmingham, B31 2AP, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Grimer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000150:complications / Q000628:therapy*; D002648:Child; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D005598:Fractures, Spontaneous / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000150:complications / Q000628:therapy*; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: Osteosarcoma; Outcomes; Pelvis