Long-term event-free survival after intensive chemotherapy for Ewing's family of tumors in children and young adults

Purpose: To improve the long-term event-free survival of patients with Ewing's family of tumors (EFTs) using high-dose, short-term chemotherapy. Patients and Methods: P6 was a prospective study of previously untreated patients with newly diagnosed EFTs. Patients received seven cycles of chemotherapy. Cycles 1, 2, 3, and 6 consisted of cyclophosphamide 2,100 mg/m²/d on days 1 and 2, and a 72-hour continuous infusion of doxorubicin 75 mg/m² and vincristine 2 mg/m² starting day 1. Cycles 4, 5, and 7 consisted of 5 consecutive days of ifosfamide 1,800 mg/m²/d and etoposide 100 mg/m²/d. Results: Sixty-eight patients were enrolled from 1991 to 2001 (median age, 18.7 years; range, 3.7 to 39.9 years). At diagnosis, 44 patients had local-regional disease, and 24 had distant metastases. The 4-year event-free survival (EFS) rate for patients with local-regional disease is 82%; overall survival (OS) is 89%. The 4-year EFS rate for patients with distant metastases is 12%; the OS rate is 17.8%. All events occurred within 51 months of diagnosis. Four patients with distant metastases had progressive disease during therapy, and no patient with local-regional disease experienced disease progression during therapy. Conclusion: Sustained EFS and OS can be achieved with intensive chemotherapy in children and young adults with local-regional EFTs. This therapy is relatively ineffective in the treatment of metastatic EFTs.