The 'other' bone sarcomas in Japan: a retrospective study of primary bone sarcomas other than osteosarcoma, Ewing sarcoma and chondrosarcoma, using data from the Bone Tumuor Registry in Japan.

Background: To date, no standard treatments for primary bone sarcomas other than those for osteosarcoma, Ewing sarcoma and chondrosarcoma have been developed.
Methods: The clinical characteristics and prognostic factors of 330 patients with primary bone sarcomas other than osteosarcoma, Ewing sarcoma and chondrosarcoma, listed in a nationwide tumour registry (Bone and Soft Tissue Tumor Registry in Japan) were investigated. The effects of adjuvant chemotherapy were determined by comparing the outcomes of patients with non-metastatic bone tumours who received surgery plus chemotherapy with those of patients who underwent surgery alone.
Results: The most common diagnosis was undifferentiated high-grade pleomorphic sarcoma. Axial site tumours (47.8%) and distant metastases at presentation (24.5%) were frequent. The 5-year overall and progression-free survival rates were 44.9 and 39.9%, respectively. Prognostic factor analysis identified surgery as an independent predictor of overall survival, and distant metastases at presentation was significant and independent predictor of both overall and progression-free survival. No significant difference in outcome was observed between patients treated with surgery alone and those treated with surgery plus chemotherapy (P = 0.71).
Conclusions: Patients with bone sarcomas other than osteosarcoma, Ewing sarcoma and chondrosarcoma without metastasis at presentation have a relatively good prognosis with definitive surgery; however, the benefit of adjuvant chemotherapy is unclear.
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