Therapy for localized Ewing's sarcoma of bone

Fifty-two previously untreated patients with localized Ewing's sarcoma of bone were treated with nonintensive chemotherapy in combination with surgery or radiation therapy (RT). RT was delivered to limited volumes in a dose dependent on the initial response to induction chemotherapy (30 to 35 Gy v 50 to 55 Gy). Fifty of the 52 patients achieved complete or partial responses with induction chemotherapy, with one nonresponding patient rendered free of tumor with surgery. Fifty patients were evaluable for local control of tumor and overall response to protocol therapy. Seventeen relapses have occurred; three metastatic, four local plus metastatic, and ten local. Two factors predicted worse disease-free survival: high WBC count (P = .03) and size of primary tumor (P = .05). Of the 14 local recurrences, 12 occurred in 28 patients who presented with primary tumors > 8 cm in size while only two of 22 patients with lesions < 8 cm had local recurrence. The Kaplan-Meier estimate of disease-free survival at 3 years is 82% for those with small lesions and 64% for those with larger lesions. Site of primary was of no prognostic value (P = .27). The 5-year survival estimate for all patients is 80% (median time on study, 3.3 years).