title: Treatment outcomes of Japanese patients with Ewing sarcoma: differences between skeletal and extraskeletal Ewing sarcoma.
abstract: OBJECTIVE
  The incidence of Ewing sarcoma is lower in non-Caucasian populations, compared with Caucasian populations, for unknown reasons. Most studies from western countries have reported improvement in outcomes following multi-agent chemotherapy, with no difference in outcome between skeletal and extraskeletal Ewing sarcoma. However, there are few studies of Ewing sarcoma in non-Caucasian populations, with especially few comparing outcomes between skeletal and extraskeletal Ewing sarcoma. Thus, the purpose of this study is to determine whether the outcomes and prognostic factors of Ewing sarcoma in the Japanese population are similar to those in Caucasian populations and to determine whether skeletal and extraskeletal Ewing sarcoma have similar outcomes in Japanese patients.
  
  
  METHODS
  We retrospectively evaluated the outcomes of 74 Japanese patients with Ewing sarcoma treated between 1981 and 2011 from the Osaka University Orthopaedic Oncology Group.
  
  
  RESULTS
  Extraskeletal Ewing sarcoma, tumors in the extremities, localized disease at presentation and diagnosis after 2000 were significantly associated with a favorable outcome. Among patients with localized disease at presentation, a significantly better outcome was observed for those with extraskeletal Ewing sarcoma, those who underwent a VDC/IE based or VAIA chemotherapy protocol, and those who were diagnosed after 2000. In the multivariable analyses, extraskeletal Ewing sarcoma was an independent predictor of increased overall survival among all patients and the subset of patients with localized disease.
  
  
  CONCLUSIONS
  The outcome of patients with Ewing sarcoma in Japan has improved in the last decade. The outcomes and prognostic factors are similar for Japanese and Caucasian patients, though in this series of Japanese patients, a better prognosis was observed for patients with extraskeletal rather than skeletal Ewing sarcoma.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takenaka
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka nnaka@ort.med.osaka-u.ac.jp.
authors.forename: Norifumi
authors.initials: N
authors.lastname: Naka
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka Department of Orthopaedic Surgery, Yukoukai General Hospital, Osaka.
authors.forename: Hideto
authors.initials: H
authors.lastname: Obata
authors.affiliation: Department of Orthopaedic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka Department of Orthopaedic Surgery, Kawachi General Hospital, Osaka.
authors.forename: Susumu
authors.initials: S
authors.lastname: Joyama
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Hamada
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Imura
authors.affiliation: Department of Orthopaedic Surgery, Osaka National Hospital, Osaka.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kakunaga
authors.affiliation: Department of Orthopaedic Surgery, Himeji Red Cross Hospital, Hyogo, Japan.
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: Department of Orthopaedic Surgery, Osaka National Hospital, Osaka.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ueda
authors.affiliation: Department of Orthopaedic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Araki
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D044466:Asian People; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003609:Dactinomycin / Q000627:therapeutic use; D004317:Doxorubicin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007069:Ifosfamide / Q000627:therapeutic use; D007223:Infant; D007564:Japan; D035002:Lower Extremity / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate; D016896:Treatment Outcome; D034941:Upper Extremity / Q000473:pathology; D014750:Vincristine / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D003609:Dactinomycin; D014750:Vincristine; D004317:Doxorubicin; D007069:Ifosfamide
keywords: extraskeletal Ewing sarcoma; outcome; race