Original Research Survival after high-dose chemotherapy for refractory and recurrent Ewing sarcoma

Background: outcome of primary refractory or recurrent Ewing sarcoma (RRES) is poor and the role of high-dose therapy (HDT) remains uncertain. We retrospectively reviewed all patients treated for RRES in the London Sarcoma Service (LSS) over a 22-year period with the aim of adding to the current literature and developing a prognostic risk score to aid clinical decision-making. Methods and results: One hundred and ninety-six patients were included; 64 patients received HDT, 98 standard non-HDT chemotherapy and 34 no systemic therapy. At RRES, median age was 20 years and seventy-four per cent of patients had progressed or relapsed within 24 months. Median overall survival for HDT and non-HDT patients was 76 months (95% CI 34.8-117.2) and 10.5 months (95% CI 8.9-12.1), respectively. Two and five-year post-relapse survival (PRS) for HDT patients was 67.9% (SE 5.9) and 52.7% (SE 6.5), and for non-HDT patients, 20.5% (SE 4.2) and 2% (SE 1.5). Four prognostic factors significant on multivariate analysis were assigned a score of one point each, creating good (score 0), intermediate (score 1-2) and poor (score 3-4) prognosis groups. The increased score was significantly associated with reduced PRS. Conclusion: Our study demonstrates that in RRES, HDT is associated with superior outcomes compared with non-HDT chemotherapy. RRES patients can be risk-stratified according to a predictive prognostic index we have developed, with the potential benefit of HDT observed even in patients with poor prognostic scores. Crown Copyright (c) 2022 Published by Elsevier Ltd. All rights reserved.

Automated summary

This study retrospectively reviewed patients with primary refractory or recurrent Ewing sarcoma and found that high-dose therapy (HDT) is associated with better outcomes compared to non-HDT chemotherapy. The study also developed a prognostic risk score to aid clinical decision-making.