Clinical features and outcome of initially unresected nonmetastatic pediatric nonrhabdomyosarcoma soft tissue sarcoma.

PURPOSE: To describe the clinical features, response to therapy, and outcome of pediatric patients with initially unresected nonmetastatic nonrhabdomyosarcoma soft tissue sarcoma (NRSTS). PATIENTS AND METHODS: We retrospectively reviewed the presenting clinical features and tumor characteristics of all 40 pediatric patients with initially unresected nonmetastatic NRSTS who were seen at our institution between March 1962 and December 1996. A subset of 27 patients for whom complete treatment information was available was analyzed to determine whether response to therapy was associated with local disease control and event-free and overall survival. RESULTS: More than 70% of the 40 patients had tumors with high-risk features (tumor size > 5 cm, high grade, invasiveness). For the 27 patients included in the outcome analysis, 5-year event-free survival and survival estimates were 33% +/- 9% and 56% +/- 10%, respectively. Ten (37%) of these patients had a complete or partial response to neoadjuvant chemotherapy and/or radiotherapy, and only two of the 10 had residual tumor after surgery. Combined chemotherapy and radiotherapy seemed more effective than either modality alone in inducing a response, but the response to neoadjuvant therapy did not predict outcome. Most treatment failures were local, and postrelapse survival was poor (19% +/- 10%). CONCLUSION: Initially unresected NRSTS constitutes a unique subgroup of pediatric sarcomas that commonly present with high-risk features and respond poorly to neoadjuvant therapy. Only about one third of patients treated with multimodal therapy remain disease-free, and local control is the major limiting factor in achieving cure. More effective risk-directed treatments are needed for this unique subgroup of patients.