Significance of surgical margin on the prognosis of patients with Ewing's sarcoma: A report from the Cooperative Ewing's Sarcoma Study

BACKGROUND. There is little information regarding an adequate surgical margin for local control of Ewing's sarcoma. METHODS. Two hundred and forty- four patients (PTS) with Ewing's sarcoma who were registered in the Cooperative Ewing's Sarcoma Studies underwent surgical treatment. Ninety- four PTS underwent definitive surgery (surgery alone), 131 PTS received postoperative irradiation, and 19 PTS received preoperative irradiation. The surgical margins were distributed as follows: radical, 29 PTS; wide, 148 PTS; marginal, 39 PTS; and intralesional, 28 PTS. The impact of the surgical margin of the treatment outcome of PTS was analyzed statistically. RESULTS. The local or combined (local recurrence and systemic metastasis) relapse rate after surgery with or without irradiation was significantly lower compared with that after definitive irradiation (irradiation alone) (7% vs. 31%, P < 0.0001). The local or combined relapse rate after complete resection (radical or wide margin) with or without irradiation was less compared with that after incomplete resection (marginal or intralesional margin) with or without irradiation (5% vs.< 12% P < 0.0455). The local or combined relapse rate did not greatly decreased after irradiation after incomplete surgery (from 14% to 12%). In both groups of good (viable tumor cells < 10%) and poor (viable cells ≤ 10%) histologic response, the difference in systemic or combined relapse rate between patients undergoing complete and incomplete surgery was not significant. The 10-year overall survival of the PTS for each of the margins was distributed as follows: radical, 58%; wide, 65%; marginal, 61%; and intralesional, 71% (P = not significant). CONCLUSIONS. Surgery in patients with Ewing's sarcoma adds to the safety of local control. Under the current treatment regimen with intensive chemotherapy and irradiation, complete resection of the tumor appears capable of decreasing the risk of local recurrence.