Vol.:(0123456789) 1 3 Clinical and Translational Oncology https://doi.org/10.1007/s12094-019-02202-y RESEARCH ARTICLE Outcomes of extraskeletal vs. skeletal Ewing sarcoma patients treated with standard chemotherapy protocol S. Salah 1  · F. Abuhijla 2  · T. Ismail 3  · S. Yaser 1  · I. Sultan 3  · H. Halalsheh 3  · A. Shehadeh 4  · S. Abdelal 4  · A. Almousa 2  · O. Jaber 5  · R. Abu‑Hijlih 2 Received: 11 July 2019 / Accepted: 9 August 2019 © Federación de Sociedades Españolas de Oncología (FESEO) 2019 Abstract Purpose To compare the outcomes of extraskeletal and skeletal Ewing sarcomas treated with standard chemotherapy protocol. Methods We retrospectively collected data on primary localized skeletal and extraskeletal ES patients. Demographics and disease characteristics were compared between the two groups. The infuence of presentation (skeletal vs. extraskeletal) on overall survival (OS) and local recurrence-free survival (LRFS) was assessed and compared by the log-rank test. Results A total of 120 patients were included; 29 (24%) had extraskeletal and 91 (76%) had skeletal ES. All patients received vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (VDC-IE) chemotherapy, with a plan for local control at week 12. At a median follow-up of 38 months, there was no diference in OS between skeletal and extraskeletal ES; 5-year OS 70% and 67% respectively, p = 0.96. Patients with extraskeletal ES had inferior 5-year LRFS compared to skeletal ES; 74% vs. 83%; p = 0.042. Local recurrence occurred at a higher frequency in the extraskeletal group; 28% vs. 11%, p = 0.034, although more extraskeletal patients received adjuvant radiotherapy; 73% vs. 36%, p = 0.01. Among patients who underwent surgery (n = 76), there was no diference in R0 resection rate (skeletal: 89%, extraskeletal: 86%, p = 0.52, or good ( ≥ 90%) tumor necrosis; skeletal: 54%, extraskeletal: 38%, p = 0.31. Conclusion Patients with localized extraskeletal ES have comparable OS outcomes to patients with skeletal ES utilizing the standard VDC-IE chemotherapy. However, extraskeletal patients are at signifcantly higher risk for local recurrence. Keywords Ewing sarcoma · Chemotherapy · Survival · Radiotherapy Introduction Ewing sarcoma (ES) is a rare malignant bone tumor that has propensity to afect children and young adults [1]. ES is characterized by specifc chromosomal translocations, t(11;22), resulting in a fusion of the EWSR1 (22q12) gene with one of the members of the ETS family of transcrip- tion factors, most commonly the FLI1 gene (11q24) in 85% of cases. A less common translocation, t (21;22), results in fusion of the EWSR1 (22q12) gene and the ERG gene (21q22) in 5–10% of cases [1, 2]. Most ES cases present with primary localized disease, whereas approximately 20–25% present with metastasis at initial diagnosis [3]. Standard therapy for localized ES includes multiagent chemotherapy and local control with surgery or radiotherapy [4–6]. The American Intergroup Ewing’s Sarcoma Trial (INT-0091—POG-8850/CCG- 7881) has shown that adding ifosfamide and etoposide (IE) to vincristine, actinomycin-D, cyclophosphamide, and Presented at the 2019 ASCO annual meeting, poster session; sarcoma, abstract no. 11027. * S. Salah samer.salahmd@gmail.com 1 Medical Oncology Department, King Hussein Cancer Center, Queen Rania Al Abdullah St 202, Amman 11941, Jordan 2 Department of Radiation Oncology, King Hussein Cancer Center, Amman, Jordan 3 Department of Pediatric Oncology and Hematology, King Hussein Cancer Center, Amman, Jordan 4 Department of Orthopedic Surgery, King Hussein Cancer Center, Amman, Jordan 5 Department of Pathology, King Hussein Cancer Center, Amman, Jordan