EXTRASKELETAL OSTEOSARCOMA: CLINICO-PATHOLOGIC FEATURES AND RESULTS OF MULTIMODAL MANAGEMENT

Abstract

Introduction: Extraskeletal osteosarcoma is a rare malignant tumor of the soft tissues. Overall, this malignancy has been associated with worse local control and overall survival rates than its skeletal counterpart despite multimodal approach. Purpose of this study was to review a single Institution experience and analyse results of management to identify factors affecting the outcome.

Methods: Retrospective study of 48 patients observed between 1966 and 2007 was undertaken. Of the total, 36 patients were admitted and managed at our Institution while 12 patients were sent for consultation and therefore not included in this study. Clinico-pathologic features and details of treatment of all 36 patients were reviewed and correlated with outcome. Updated follow-up was available in all patients.

Results: There were 21 males and 15 females, mean age was 53.6+/−19.3 years (range 14–84 yrs); 23 patients (63.9%) presented with localised disease while distant metastases were present in 13 patients (36.1%). Surgery consisted of a limb-salvage procedure in 25 patients (69.4%), amputation in 9 patients (25%) and 2 patients were considered inoperable (5.6%). Postoperative radiation therapy was given to 6 patients (16.7%) and multiagent chemotherapy administered to 19 patients (52.8%). At mean follow-up of 5.8 years, 23 patients had died of disease, expected 5 and 10 year overall survival rates were 41% and 31%. Tumor size and age at presentation were the most important predictors of survival while chemotherapy showed a trend towards improved survival in patients with localised disease.

Discussion and Conclusion: Extraskeletal osteosarcoma was associated with substantially worse prognosis than skeletal osteosarcoma despite multimodal management.