Does Radiotherapy after Surgery Affect Outcomes in Ewing's Sarcoma of the Pelvis?

BACKGROUND: The impact of postoperative radiotherapy (PORT) on outcomes has been a matter of debate after adequate resection in Ewing's sarcoma of the pelvis. We evaluated our cases after surgical excision in pelvic Ewing's sarcoma and assessed local control and overall survival (OS) with respect to PORT and chemotherapy-induced percentage necrosis. MATERIALS AND METHODS: Forty four surgically operated patients (June 2002–November 2014) of localized Ewing's sarcoma were retrospectively reviewed. There were 31 males and 13 females. Age ranged from 2 to 53 years. All patients received institutional chemotherapy protocol. No patient received preoperative radiotherapy. Specimen was analyzed for margins and chemotherapy-induced percentage necrosis. PORT was offered to patients on case-by-case basis. Presence of a large preoperative soft-tissue component, margin evaluation, and percentage necrosis were factors considered. At time of the last followup, 29 patients were alive, 11 died, and 4 were lost to followup. Survivors had a minimum followup of 2 years (range: 31–118 months, mean = 69 months). RESULTS: One of twenty (5%) patients with PORT had a local recurrence as against 2 of 24 (8%) without PORT. OS of all patients was 76% at 5 years. Twelve patients with <90% necrosis had OS of 56% and 32 with >90% necrosis had OS of 83% (P = 0.040). OS of patients with PORT was 74%, without PORT was 78% (P = 0.629). CONCLUSIONS: The decision to offer PORT after surgical excision in pelvic Ewing's sarcoma is multifactorial; the absence of PORT in selected cases is not detrimental to local control. Poor responders to chemotherapy had poorer survival while PORT did not impact on outcomes.