The impact of local control timing in Ewing sarcoma.

Abstract

To assess the impact of delay in local control on survival outcomes of Ewing sarcoma (ES) patients. The cornerstone of therapy of localized ES includes chemotherapy and local control with surgery or radiotherapy. We sought to assess the impact of delay (>15 weeks) in timing of local control on survival outcomes of ES patients. Data of consecutive patients with primary non-metastatic ES of the extremities, treated at a single institution were collected. The impact of delay of timing for local control, demographics, and disease characteristics on overall survival (OS) was analyzed. A total of 43 patients with ES of the extremity were included. All patients received neoadjuvant chemotherapy. Local control was by surgery in 36 patients and definitive radiation in 7. A total of 16 patients had delay in local control. At a median follow of up of 48 months, patients with delay in local control had significantly inferior OS compared to those with optimal local control timing (5-year OS 56% vs. 80%, respectively, p = 0.044). Other factors that predicted inferior OS included definitive radiation as opposed to definitive surgery (5-year OS 25% vs. 79%, respectively, p = 0.041) and tumor necrosis <90% as opposed to ≥90% (5-year OS 55% vs. 90%, respectively, p = 0.01). Delay in definitive therapy, local control with radiation as opposed to surgery and poor post-chemotherapy tumor necrosis predict inferior OS in ES. Adopting strategies to minimize delay in local control could improve survival outcomes.