Purpose: The aim of the study was to determine the impact of negative but close resection margins on local recurrence in children with extraskeletal Ewing sarcoma (EES).
Method: We reviewed records of 32 patients with EES treated between March 2005 and March 2013. All patients except one underwent surgical excision either upfront or after induction chemotherapy. Patients with viable tumor and negative surgical margins, which were categorized as less than or greater than 1 cm, were selected. Local control and survival analysis were performed for patients in both the groups.
Results: The 5-year event-free and overall survival rates of entire cohort is 68 and 77 %, respectively. Surgical margins were negative in 23/26 (90.3 %) patients. There were no local recurrences in any of the patients with margins of less than 1 cm. Only one patient with a margin greater than 1 cm had a local recurrence along with distant metastases. A tumor-free margin of more than 1 cm did not affect overall or event-free survival (p = NS).
Conclusion: Optimal local control is feasible in children with EES regardless of the quantitative extent of negative margins. Achieving a three-dimensional tumor-free margin should be the goal of surgical resection.