High-Dose Chemotherapy With Stem Cell Support

Aggressive attempts to control the disease, including myeloablative regimens, have been used, but there is no evidence at this time to conclude that myeloablative therapy is superior to standard chemotherapy.[41-43]; [44][Level of evidence C2]

Most published reports about the use of high-dose therapy and stem cell support for patients with high-risk Ewing sarcoma have significant flaws in methodology. The most common issue is the comparison of this high-risk group with an inappropriate control group. Patients with Ewing sarcoma at high risk of treatment failure who received high-dose therapy are compared with patients who did not receive high-dose therapy. Patients who undergo high-dose therapy must respond to systemic therapy, remain alive and respond to treatment long enough to reach the time at which stem cell therapy can be applied, be free of comorbid toxicity that precludes high-dose therapy, and have an adequate stem cell collection. Patients who undergo high-dose therapy and stem cell support are a highly selected group. Comparing this patient group with all patients with high-risk Ewing sarcoma is inappropriate and leads to the erroneous conclusion that this strategy improves outcome.

Surveys of patients who underwent allogeneic hematopoietic stem cell transplant (HSCT) for recurrent Ewing sarcoma did not show improved EFS when compared with patients who underwent autologous HSCT. In addition, allogeneic HSCT was associated with a higher complication rate.[41,45,46]