Role of High-Dose Chemotherapy and Autologous Hematopoietic Cell Transplantation for Children and Young Adults with Relapsed Ewing's Sarcoma: A Systematic Review

Background. Relapsed Ewing's sarcoma (RES) is an aggressive malignancy with poor survival. Although high-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) given after conventional chemotherapy (CC) has shown survival benefits, it is not generally used in the United States for RES. We performed a systemic review to evaluate the benefits of HDCT for RES. Methods. Literature search involved Medline, Embase, and Cochrane database. We included studies with RES patients treated with HDCT/ASCT. Results. Twenty-four studies with total of 345 reported RES patients that got HDCT were included in final analysis. Seventeen studies had patients with multiple malignancies including RES, while seven had only RES patients. At 2 and 3-5 years, event-free survival (EFS) in studies with only RES patients ranged 42-47% and 20-61% and overall survival (OS) ranged 50-66% and 33-77%, respectively. In studies with combined patients that reported outcomes of RES separately, the EFS at 1-3 and 4 years was 36-66% and 17-50%, respectively. The OS at 1-2 and 3-4 years was 40-60% and 50-70%. Conclusions. Most studies using HDCT/ASCT as consolidation regimen showed improved survival benefits compared to CC. Randomized controlled studies are needed to determine true clinical benefits of HDCT followed by ASCT in patients with RES.