Post-relapse survival in patients with Ewing sarcoma.

Area of Science:

• Pediatric Oncology
• Sarcoma Research
• Clinical Trials

Background:

• Ewing sarcoma (EWS) poses significant challenges, particularly upon relapse.
• High-risk EWS patients often receive high-dose chemotherapy (HDT) with busulfan and melphalan as initial consolidation.
• Evaluating post-relapse survival (PRS) is crucial for refining treatment strategies.

Purpose of the Study:

• To assess the impact of HDT consolidation on post-relapse survival (PRS) in Ewing sarcoma (EWS) patients.
• To identify factors influencing PRS in EWS patients experiencing recurrence.
• To analyze the efficacy of second-line chemotherapy regimens.

Main Methods:

• Retrospective analysis of EWS patients from ISG/SSG III and IV trials who relapsed after complete remission.
• Inclusion of patients receiving high-dose ifosfamide chemotherapy at recurrence.
• Consolidation with HDT was administered to responders who had not previously received it.

Main Results:

• 107 EWS patients were analyzed; median relapse-free interval (RFI) was 18 months.
• Prior HDT was associated with shorter RFI and lower likelihood of achieving a second complete remission (CR2).
• Five-year PRS was 19%; achieving CR2 improved 5-year PRS to 48%. Younger age, lung-only recurrence, and RFI > 24 months improved PRS.

Conclusions:

• Post-relapse survival in EWS is influenced by age, recurrence pattern, RFI, and response to second-line therapy.
• Consolidation with HDT did not demonstrate a survival advantage for recurrent EWS.
• Further research is needed to optimize salvage strategies for relapsed EWS.