The response of Ewing's sarcoma to sequential cyclophosphamide and adriamycin induction therapy.

Twenty-four consecutive patients with Ewing's sarcoma were treated in a protocol designed to deliver induction chemotherapy with postinduction surgical-pathologic evaluation of the primary tumor site. This was followed by delayed radiotherapy, the dose and port of which was dependent on the response to induction chemotherapy. All patients received 5 courses of sequential cyclophosphamide and adriamycin during the 3-mo induction period. Nineteen of 23 evaluable patients had no gross residual tumor following this therapy. Of the remaining 4, 2 had complete surgical excision of residual gross disease. Of the 22 patients who were free of gross tumor following induction chemotherapy and surgery, 5 received no radiotherapy, 16 received moderate-dose limited port radiotherapy (3000-3500 R), and 1 received high-dose limited port radiotherapy (5000 R). All 14 patients with localized disease attained remission and are surviving 9-41+ mo (median 21+) with 2 local recurrences occurring after 10 and 33 mo of remission. Of the 10 patients presenting with metastatic disease, 8 attained complete remission with 4 of the 8 remaining disease-free 12-34+ mo from diagnosis. This study indicates that Ewing's sarcoma is very sensitive to moderate-dose 2 drug chemotherapy of low toxicity and that it is possible to delay radiotherapy and any extensive surgical procedure until remission is induced.