Results of the EICESS-92 Study : two randomized trials of Ewing's sarcoma treatment : cyclophosphamide compared with ifosfamide in standard-risk patients and assessment of benefit of etoposide added to standard treatment in high-risk patients

PURPOSE: The European Intergroup Cooperative Ewing's Sarcoma Study investigated whether cyclophosphamide has a similar efficacy as ifosfamide in standard-risk (SR) patients and whether the addition of etoposide improves survival in high-risk (HR) patients. PATIENTS AND METHODS: SR patients (localized tumors, volume or=100 mL or metastases) were randomly assigned to receive 14 courses of either VAIA or VAIA plus etoposide (EVAIA). Outcome measures were event-free survival (EFS; defined as the time to first recurrence, progression, second malignancy, or death) and overall survival (OS). RESULTS: A total of 647 patients were randomly assigned: 79 SR patients were assigned to VAIA, 76 SR patients were assigned to VACA, 240 HR were assigned to VAIA, and 252 HR patients were assigned to EVAIA. The median follow-up was 8.5 years. In the SR group, the hazard ratios (VACA v VAIA) for EFS and OS were 0.91 (95% CI, 0.55 to 1.53) and 1.08 (95% CI, 0.58 to 2.03), respectively. There was a higher incidence of hematologic toxicities in the VACA arm. In the HR group, the EFS and OS hazard ratios (EVAIA v VAIA) indicated a 17% reduction in the risk of an event (95% CI, -35% to 5%; P = .12) and 15% reduction in dying (95% CI, -34% to 10%), respectively. The effect seemed greater among patients without metastases (hazard ratio = 0.79; P = .16) than among those with metastases (hazard ratio = 0.96; P = .84). CONCLUSION: Cyclophosphamide seemed to have a similar effect on EFS and OS as ifosfamide in SR patients but was associated with increased toxicity. In HR patients, the addition of etoposide seemed to be beneficial.