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.

Automated summary

In the study of patients with primary bone sarcomas other than osteosarcoma, Ewing sarcoma, and chondrosarcoma, it was found that surgery was an independent predictor of overall survival, while distant metastases at presentation were significant predictors of both overall and progression-free survival. There was no significant difference in outcomes between patients treated with surgery alone and those treated with surgery plus chemotherapy.