title: Osteosarcoma of the pelvis: experience of the Cooperative Osteosarcoma Study Group.
abstract: OBJECTIVE
  To define patients and tumor characteristics as well as therapy results, patients with pelvic osteosarcoma who were registered in the Cooperative Osteosarcoma Study Group (COSS) were analyzed.
  
  
  METHODS
  Sixty-seven patients with a high-grade pelvic osteosarcoma were eligible for this analysis. Fifteen patients had primary metastases. All patients received chemotherapy according to COSS protocols. Thirty-eight patients underwent limb-sparing surgery, 12 patients underwent hemipelvectomy, and 17 patients did not undergo definitive surgery. Eleven patients received irradiation to the primary tumor site: four postoperatively and seven as the only form of local therapy.
  
  
  RESULTS
  Local failure occurred in 47 of all 67 patients (70%) and in 31 of 50 patients (62%) who underwent definitive surgery. Five-year overall survival (OS) and progression-free survival rates were 27% and 19%, respectively. Large tumor size (P =.0137), primary metastases (P =.0001), and no or intralesional surgery (P <.0001) were poor prognostic factors. In 30 patients with no or intralesional surgery, 11 patients with radiotherapy had better OS than 19 patients without radiotherapy (P =.0033). Among the variables, primary metastasis, large tumor, no or intralesional surgery, no radiotherapy, existence of primary metastasis (relative risk [RR] = 3.456; P =.0009), surgical margin (intralesional or no surgical excision; RR = 5.619; P <.0001), and no radiotherapy (RR = 4.196; P =.0059) were independent poor prognostic factors.
  
  
  CONCLUSIONS
  An operative approach with wide or marginal margins improves local control and OS. If the surgical margin is intralesional or excision is impossible, additional radiotherapy has a positive influence on prognosis.
authors.affiliation: Department of Orthopaedic Surgery, Westfälische Wilhelms-University, Münster, Germany. tozaki@md.okayama-u.ac.jp
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
authors.forename: Silke
authors.initials: S
authors.lastname: Flege
authors.forename: Matthias
authors.initials: M
authors.lastname: Kevric
authors.forename: Norbert
authors.initials: N
authors.lastname: Lindner
authors.forename: Rainer
authors.initials: R
authors.lastname: Maas
authors.forename: Günter
authors.initials: G
authors.lastname: Delling
authors.forename: Rudolf
authors.initials: R
authors.lastname: Schwarz
authors.forename: Arthur R
authors.initials: AR
authors.lastname: von Hochstetter
authors.forename: Mechthild
authors.initials: M
authors.lastname: Salzer-Kuntschik
authors.forename: Wolfgang E
authors.initials: WE
authors.lastname: Berdel
authors.forename: Heribert
authors.initials: H
authors.lastname: Jürgens
authors.forename: G Ulrich
authors.initials: GU
authors.lastname: Exner
authors.forename: Peter
authors.initials: P
authors.lastname: Reichardt
authors.forename: Regine
authors.initials: R
authors.lastname: Mayer-Steinacker
authors.forename: Volker
authors.initials: V
authors.lastname: Ewerbeck
authors.forename: Rainer
authors.initials: R
authors.lastname: Kotz
authors.forename: Winfried
authors.initials: W
authors.lastname: Winkelmann
authors.forename: Stefan S
authors.initials: SS
authors.lastname: Bielack
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy; D012516:Osteosarcoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D010384:Pelvic Bones; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate; D017211:Treatment Failure; D016896:Treatment Outcome