Does consolidation with autologous stem cell transplantation improve the outcome of children with metastatic or relapsed Ewing sarcoma?

Abstract

Objective: To evaluate the role of high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) as consolidation therapy for children with high-risk Ewing sarcoma (ES) treated at The Hospital for Sick Children (SickKids), Toronto.

Patients and methods: The charts of children treated for high-risk ES (defined as metastatic at diagnosis or relapsed) between 1990 and 2005 at SickKids were reviewed. Forty-five children were identified. Twenty patients received ASCT after induction with vincristine, doxorubicin, ifosfamide, cyclophosphamide, and etoposide. Patients with resectable tumor or lung metastases underwent surgery and those with non-resectable tumors were treated with irradiation. Twenty-five patients were treated with conventional chemotherapy (CC). Primary metastatic patients were treated with either a local protocol or as per POG 9354. At relapse, patients were treated with topotecan, cyclophosphamide, then ifosfamide, carboplatin, and etoposide (ICE). Local control was attained with surgery and/or irradiation.

Results: Ten of the 20 patients treated with ASCT are alive (median follow-up 6 years), with 8/10 being in remission more than 5 years from diagnosis. The 3-year overall survival (OS) for ASCT was 59%, (95% CI: 36%, 81%) compared to 34% (14%, 53%) for patients treated with CC (P-value = 0.06). The 3-year event-free survival (EFS) for the ASCT was 39% (17%, 60%) compared to 32% (13%, 50%) in the CC group (P = 0.08).

Conclusion: ASCT appears to add some benefit to conventional multimodality therapy for children with high-risk ES. Randomized controlled trials are warranted.