title: Chemotherapy response is an important predictor of local recurrence in Ewing sarcoma.
abstract: BACKGROUND
  Local recurrence in Ewing sarcoma is associated with a poor prognosis. The purpose of the study was to determine the factors that predict local recurrence after surgical treatment of the primary tumor.
  
  
  METHODS
  Between 1990 and 2001, 64 patients underwent surgical resection of Ewing sarcoma. Surgical margins were assessed histologically and radiologically. Response to preoperative chemotherapy was determined by detailed specimen mapping. Local recurrence-free survival (LRFS) was calculated by Kaplan-Meier analysis. Multivariate analysis was performed with the Cox proportional hazards model.
  
  
  RESULTS
  A number of factors were found to be associated with local recurrence on univariate analysis. Patients with a good response to chemotherapy (> or = 90% tumor necrosis), had superior LRFS at 5 years (86% vs 51%, P = .015). Central site of disease was associated with an increased rate of recurrence. The LRFS at 5 years was 50% for the chest wall, 74% for pelvic/scapular, and 86% for extremity tumors (P = .083). Positive surgical margin was not a strong predictor of recurrence (P = .72). A critical analysis of minimal surgical margin based on preoperative magnetic resonance imaging (MRI) and computed tomography (CT) scans also failed to reveal an association between margin and local recurrence. In multivariate analysis, the 2 independent predictors of local recurrence were histological response to chemotherapy and central site of disease.
  
  
  CONCLUSIONS
  Local recurrence after surgical resection is a complex phenomenon. An important predictive factor is the response to chemotherapy. In the current study, this seems to have the largest impact. Central site of disease may be a second independent predictive factor.
authors.affiliation: Department of Orthopaedic Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77230, USA. plin@mdanderson.org
authors.forename: Patrick P
authors.initials: PP
authors.lastname: Lin
authors.forename: Norman
authors.initials: N
authors.lastname: Jaffe
authors.forename: Cynthia E
authors.initials: CE
authors.lastname: Herzog
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Costelloe
authors.forename: Michael T
authors.initials: MT
authors.lastname: Deavers
authors.forename: Jeana S
authors.initials: JS
authors.lastname: Kelly
authors.forename: Shreyaskumar R
authors.initials: SR
authors.lastname: Patel
authors.forename: John E
authors.initials: JE
authors.lastname: Madewell
authors.forename: Valerae O
authors.initials: VO
authors.lastname: Lewis
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Cannon
authors.forename: Robert S
authors.initials: RS
authors.lastname: Benjamin
authors.forename: Alan W
authors.initials: AW
authors.lastname: Yasko
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000188:drug therapy; D009367:Neoplasm Staging; D011379:Prognosis; D011859:Radiography; D012512:Sarcoma, Ewing / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000601:surgery; D015996:Survival Rate; D016896:Treatment Outcome