e23507 Background: Ewing sarcoma is an aggressive primary bone malignancy that arises in various anatomic locations. While treatment typically involves multimodal therapy including chemotherapy, surgery, and radiation, it remains unclear whether anatomic location impacts surgical feasibility, treatment approach, and outcomes. This study evaluated the association between anatomic location and surgical and oncologic outcomes in patients with Ewing sarcoma. Methods: We performed a retrospective cohort study of 46 patients with Ewing sarcoma treated at a single institution. Patients were stratified by primary tumor location: lower extremity (n = 30, 65%), pelvis (n = 12, 26%), and upper extremity (n = 4, 9%). A secondary analysis evaluated extremity subgroups (proximal, middle, distal). Outcomes included surgical approach (limb salvage, amputation, or non-operative), radiation therapy utilization, margin status, complications, local recurrence, metastatic presentation, and mortality. Results: Anatomic location significantly influenced treatment strategy. Pelvic tumors were more likely to receive neoadjuvant radiation compared with lower extremity tumors (41.7% vs 0%, p = 0.001) and were less likely to undergo surgical resection (41.7% vs 90.0% limb salvage, p = 0.006). Upper extremity tumors had the highest rate of adjuvant radiation (50.0% vs 6.7% lower extremity, p = 0.042). All surgical patients achieved negative (R0) margins. Pelvic tumors demonstrated worse oncologic outcomes, including higher mortality (41.7% vs 16.7% lower extremity), higher rates of metastatic disease upon presentation (33.3% vs 13.3%), and increased wound complications (40% vs 11%), though these differences did not reach statistical significance. Lower extremity tumors achieved the lowest mortality (16.7%) with upper extremity tumors exhibiting a 50% mortality rate, although limited by a small sample size (n = 4). Extremity subgroup analysis (proximal n = 20, distal n = 11, middle n = 3) demonstrated proximal tumors had highest implant failure (33.3% vs 9.1% distal) while distal had highest metastatic presentation (27.3% vs 10.0% proximal). Overall cohort characteristics: mean age 21.4 years, mean tumor size 8.0 cm, mean follow-up 80.8 months, overall mortality 26.1%. Conclusions: Primary tumor location significantly impacts treatment approach and demonstrates meaningful trends toward differential outcomes in Ewing sarcoma. Pelvic tumors require more aggressive multimodal therapy, are less frequently resectable, and are associated with higher complications and poorer survival. In contrast, lower extremity tumors achieve highly successful limb salvage rates and favorable survival. These findings highlight the importance of anatomic location in treatment planning, risk stratification, and patient counseling for those with Ewing sarcoma.
Salih et al. (Thu,) studied this question.