Extraskeletal osteosarcoma an international rare cancer network study

Terence T. Sio, Charles C. Vu, Schoeb Sohawon, Paul Van Houtte, Juliette Thariat, Paul J. Novotny, Robert C. Miller, Gil Bar-Sela

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Objectives: To report characteristics, treatment, and outcomes for an international cohort of patients with extraskeletal osteosarcoma (ESOS). Materials and Methods: Through the Rare Cancer Network, retrospective data on patients with ESOS were collected. Patient characteristics, multimodality treatment information, and survival status were analyzed. Results: Thirty-seven patients in 4 health care institutions were identified. Thirty-one (86%) patients had grade 3 or 4 tumors. Most patients (27 [73%]) had stage III disease. Fourteen (38%) received neoadjuvant chemotherapy or chemoradiation. Of 28 (85%) who underwent surgery, 21 (75%) had free margins achieved and 15 (41%) subsequently received adjuvant chemotherapy. At median follow-up of 45 months, 20 (55%) patients were alive, 13 (43%) of whom were disease free. Univariate analysis showed that poor overall survival was related to stage IV (P < 0.001), no surgery (P < 0.001), primary size >10 cm (P = 0.002), and age (P = 0.002). In multivariate analysis, primary size >10 cm (P = 0.005) was prognostic for overall survival. For patients without metastases, univariate analysis showed disease-free survival (DFS) related to primary size >10 cm (P = 0.003), surgery (P = 0.004), local recurrence (P = 0.003), and age (P < 0.001). In multivariate analysis for DFS, primary size >10 cm (P = 0.01) and older age (P < 0.001) were significant for worse outcome. Conclusions: Multimodality treatment remains standard for localized ESOS, with indications for neoadjuvant therapy less clear. Larger tumor size and older age were prognostic of poorer DFS.

Original languageEnglish (US)
Pages (from-to)32-36
Number of pages5
JournalAmerican Journal of Clinical Oncology: Cancer Clinical Trials
Issue number1
StatePublished - 2016


  • Extraskeletal osteosarcoma
  • Multimodality therapy
  • Outcome
  • Rare Cancer Network
  • Soft-tissue sarcoma

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


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