title: Prognostic effect of pathologic fracture in localized osteosarcoma: a cohort/case controlled study at a single institute.
abstract: BACKGROUND
  The negative prognostic role of pathologic fracture in osteosarcoma is not determined, as previous case-control and retrospective cohort studies have produced contradictory results.
  
  
  METHODS
  We conducted both cohort (n = 384) and case-control (n = 111) studies on 37 pathologically fractured localized osteosarcoma of extremity.
  
  
  RESULTS
  In cohort study, patients with a fracture showed a tendency of poorer survival, but the difference did not reach the level of significance (5-year metastasis-free survival rates; 48% for cases vs. 61% for controls; P = 0.06). A case-control study on 37 fractured and 74 control recruited from 347 patients matched for tumor size and location showed no survival difference between the cases and controls (P = 0.12).
  
  
  CONCLUSIONS
  Reported negative prognostic effect of a pathologic fracture is likely to be due to confounding by tumor size and location. The present study suggests that the presence of a pathologic fracture has no prognostic relevance.
authors.affiliation: Department of Pathology, Korea Cancer Center Hospital, Seoul 139-706, Korea.
authors.forename: Min S
authors.initials: MS
authors.lastname: Kim
authors.forename: Soo-Yong
authors.initials: SY
authors.lastname: Lee
authors.forename: Tae R
authors.initials: TR
authors.lastname: Lee
authors.forename: Wan H
authors.initials: WH
authors.lastname: Cho
authors.forename: Won S
authors.initials: WS
authors.lastname: Song
authors.forename: Sang H
authors.initials: SH
authors.lastname: Cho
authors.forename: Jun A
authors.initials: JA
authors.lastname: Lee
authors.forename: Ji Y
authors.initials: JY
authors.lastname: Yoo
authors.forename: Sung T
authors.initials: ST
authors.lastname: Jung
authors.forename: Dae-Geun
authors.initials: DG
authors.lastname: Jeon
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D050723:Fractures, Bone / Q000473:pathology* / Q000628:therapy; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012516:Osteosarcoma / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D016019:Survival Analysis