Adjuvant therapy for sarcomas.

Abstract

Adjuvant therapy is currently established in the treatment of osteosarcoma, Ewing's sarcoma and rhabdomyosarcoma. Of the 12 reported randomized studies of adjuvant chemotherapy for soft tissue sarcoma, only 2 show a significant overall survival advantage for chemotherapy (the most important endpoint). In three randomized trials, the survival of the observation arm exceeds that of the chemotherapy arm. In two additional studies, subset analyses currently indicate a significant DFS advantage for adjuvant chemotherapy in extremity lesions, but no significant improvement in survival. Although initial NCI reports showed significantly prolonged survival for the subset of chemotherapy-treated extremity primaries, survival on longer follow-up is no longer significantly different. In the subset analysis of retroperitoneal sarcomas in the same NCI study, the survival of the control group is superior to the treatment group. Doxorubicin associated cardiotoxicity has occurred in about 10% of treated patients, occasionally contributing to treatment-related deaths. Based on these data, adjuvant chemotherapy should be considered investigational for adult soft-tissue sarcomas of any primary site. Future randomized trials should include patients at high risk for metastases (large, high-grade lesions) with a reasonable likelihood of local control by radical resection, or resection with uninvolved margins and subsequent radiotherapy. Low-grade sarcomas are currently cured by surgical resection in 80% of cases, and thus should not be included in adjuvant trials.