Prognostic Implication of Adjuvant/neoadjuvant Chemotherapy Consisting of Doxorubicin and Ifosfamide in Patients with Extraskeletal Osteosarcoma

Extraskeletal osteosarcoma (ESOS) is an extremely rare soft tissue sarcoma. Their prognosis remains poor. Our purposes were to identify the effective chemotherapeutic regimen for ESOS. We retrospectively reviewed 16 patients with ESOS treated at the Osaka University Orthopaedic Oncology Group between 1992 and 2012. We extracted the clinical data on patients. Kaplan–Meier method and the log-rank test were used for survival analyses. Median age of the patients was 61.5 years (range 25–79 years). Wide local excision was performed for 11 patients and 9 patients were treated combined with chemotherapy. The 5-year disease-specific survival (DSS) rate was 53.9%. The 5-year DSS rates for patients treated with adjuvant/neoadjuvant chemotherapy or not were 66.7% or 25%, respectively (p = 0.0215). Furthermore, the 5-year DSS rates for patients treated with adjuvant/neoadjuvant chemotherapy consisting of doxorubicin and ifosfamide and those treated with other regimens were 100% or 40%, respectively (p = 0.0327). The present study demonstrated that adjuvant/neoadjuvant chemotherapy, especially consisting of doxorubicin and ifosfamide, was potentially efficacious for ESOS. Further prospective study using this multimodality treatment approach to patients with ESOS should be strongly warranted.