How do you approach myeloablative chemotherapy for high-risk Ewing sarcoma patients?

This question has been discussed and debated in the literature for many years. This is largely due to the lack of prospective randomized trials to properly answer the question. Even when studied in this manner, the variable definition of high-risk and study design has made establishing generalizable standard of care recommendations challenging. For example, in the recently published results from the Euro-E.W.I.N.G.99 and EWING-2008 trials (Whelan et al J Clin Oncol. 2018 Nov 1; 36(31): 3110–3119; Dirksen et al. J Clin Oncol. 2019 Dec 1;37(34):3192-3202), 2 different categories of high-risk patients were identified. One included those with localized disease but poor histologic response (≥ 10% viable cells) after induction chemotherapy or ini...