OBJECTIVES: I. Compare the effects of dose intensive regimens of vincristine, doxorubicin, cyclophosphamide, and dexrazoxane with or without ImmTher (a muramyl dipeptide liposome) on the 2 year disease-free survival of patients with newly diagnosed high risk Ewing's sarcoma. II. Evaluate the feasibility and determine the toxicity of administering weekly ImmTher for 1 year to these patients. III. Determine which therapy is worthy of further evaluation.