title: Improved Prognosis for Patients with Ewing Sarcoma in the Sacrum Compared with the Innominate Bones: The Scandinavian Sarcoma Group Experience.
abstract: BACKGROUND
  Treatment of Ewing sarcoma of the pelvic bones remains one of the most difficult tasks in the treatment of bone sarcomas. Whether surgery or radiation therapy is the best local treatment is still a matter of debate. The aim of the present study was to compare sacral and nonsacral sites with regard to the treatment and outcome of pelvic Ewing sarcomas.
  
  
  METHODS
  Patients with Ewing sarcoma of the osseous pelvis diagnosed between 1986 and 2011 were identified through the Scandinavian Sarcoma Group registry. Data regarding tumor size, local treatment (surgery or radiation therapy), metastatic disease, surgical margins, local recurrence, and overall survival were analyzed.
  
  
  RESULTS
  Of the 117 patients examined, eighty-eight had tumors in the innominate bones and twenty-nine, in the sacrum. Radiation therapy was the sole local treatment for 40% of the innominate bone tumors in contrast to 79% of the sacral tumors. The five-year disease-free survival rate in the latter group (66%) was greater than that in the group with tumors in the innominate bones (40%) (p = 0.02 adjusted for size).
  
  
  CONCLUSIONS
  Disease-free survival among patients with Ewing sarcoma was improved when the tumor was localized in the sacrum compared with the innominate bones, where these tumors are generally larger. Local radiation therapy alone appears to result in good local tumor control and may be the treatment of choice for sacral tumors.
authors: Department of Orthopaedic Surgery, Karolinska University Hospital, Solna, Sweden asle.hesla@karolinska.se.
authors: Asle Charles
authors: AC
authors: Hesla
authors: Department of Orthopaedic Surgery, Karolinska University Hospital, Solna, Sweden panagiotis.tsagkozis@karolinska.se.
authors: Panagiotis
authors: P
authors: Tsagozis
authors: Department of Oncology, Haukeland University Hospital, Bergen, Norway nina.louise.jebsen@helse-bergen.no.
authors: Nina
authors: N
authors: Jebsen
authors: Department of Orthopaedic Surgery, Norwegian Radium Hospital, Oslo, Norway olga.zaikova@me.com.
authors: Olga
authors: O
authors: Zaikova
authors: Department of Orthopaedic Surgery, Karolinska University Hospital, Solna, Sweden henrik.bauer@karolinska.se.
authors: Henrik
authors: H
authors: Bauer
authors: Department of Orthopaedic Surgery, Karolinska University Hospital, Solna, Sweden otte.brosjo@karolinska.se.
authors: Otte
authors: O
authors: Brosjö
mesh_terms: D001859:Bone Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local; D010384:Pelvic Bones; D011379:Prognosis; D011446:Prospective Studies; D012447:Sacrum; D012512:Sarcoma, Ewing / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy; D055815:Young Adult