The role of surgical margins in treatment of Ewing's sarcoma family tumors: experience of a single institution with 512 patients treated with adjuvant and neoadjuvant chemotherapy.

To evaluate the importance of surgical margins for local and systemic control of Ewing's sarcoma family tumors (ESFT). METHODS AND MATERIALS: Between 1979 and 1999, 512 patients with ESFTs entered 4 different adjuvant and neoadjuvant studies performed at a single institution. Of these patients, 335 were treated with surgery alone (196) or surgery followed by radiotherapy at doses of 44.8 Gy (139). We compared their outcome with that of the 177 patients who were locally treated by radiotherapy at 60 Gy. RESULTS: Local control (88.8% vs. 80.2%, p < 0.009) and 5-year disease-free survival (63.8% vs. 47.6%, p < 0.0007) were significantly better in patients treated with surgery and, among them, in those with adequate surgical margins (96.6% vs. 71,7%, p < 0.0008, and 69.6% vs. 46.3%, p < 0.0002). Nonetheless, better results were observed only in extremity tumors. CONCLUSIONS: Surgery is better than radiotherapy in cases of extremity ESFT with achievable adequate surgical margins, and in cases of inadequate surgical margins, adjuvant reduced-dose radiotherapy is ineffective. Therefore, when inadequate margins are expected, patients are better treated with full-dose radiotherapy from the start.