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Prognostic factors and prognosis
Source: Childhood Soft Tissue Sarcoma Treatment (PDQ®)–Health Professional Version, National Cancer Institute.
Source updated: April 21, 2025 · Captured 2026-09-09.
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Context: Treatment of Chondro-osseous Tumors / Osteosarcoma, Extraskeletal
Extraskeletal osteosarcoma is associated with a high risk of local recurrence and pulmonary metastasis.[13]
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A single-institution retrospective review identified 43 patients with extraskeletal osteosarcoma; 37 patients had localized disease, and 6 patients presented with metastatic disease. The median age was 55 years (range, 7–81 years). Seventy-five percent of patients received chemotherapy.[14]
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The median progression-free survival (PFS) was 21 months.
The median OS was 50 months.
There was a trend toward better survival for patients who received chemotherapy, and a statistically significant improvement in survival for patients who received chemotherapy that included cisplatin.
In a review of 274 patients with extraskeletal osteosarcoma, the median age at diagnosis was 57 years (range, 12–91 years).[15][Level of evidence C1]
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The 5-year DFS and OS rates were significantly better for those who received chemotherapy.
The use of an osteosarcoma-type regimen was associated with improved response rates.
The European Musculoskeletal Oncology Society performed a retrospective analysis of 266 eligible patients with extraskeletal osteosarcoma treated between 1981 and 2014. Fifty patients (19%) presented with metastatic disease.[15]
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An analysis of the 211 patients who achieved complete remission after surgical resection of the primary tumor showed a 5-year OS rate of 51% and a DFS rate of 43%.
There was a favorable trend for survival among patients who were treated with chemotherapy that is usually employed for patients with osseous osteosarcoma.
In a multivariable analysis, factors associated with better prognosis included younger age (<40 years), smaller tumors, and use of chemotherapy.
An analysis of SEER Program data from 1973 to 2009 identified 256 patients (6%) with extraskeletal osteosarcoma among 4,173 patients with high-grade osteosarcoma.[16]
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Compared with skeletal osteosarcoma, patients with extraskeletal osteosarcoma were more likely to be older, female, have an axial primary tumor, and have regional lymph node involvement.
Adverse prognostic features included presence of metastatic disease, larger tumor size, older age, and axial primary tumor site.
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Preserved source evidence · Not medical advice