PURPOSE: One hundred thirty of 2,792 patients (5%) registered on three 
Intergroup Rhabdomyosarcoma Study clinical trials (IRS-I, -II, and -III) from 
1972 to 1991 had an extraosseous Ewing's sarcoma (EOE). We report here the 
results of multimodality therapy for this tumor.
PATIENTS AND METHODS: The 130 patients were less than 21 years of age; 70 (54%) 
were males. Primary tumor sites were on the trunk in 41 patients, an extremity 
in 34, the head/neck in 23, the retroperitoneum/pelvis in 21, and other sites in 
11. One hundred fourteen patients had no metastases at diagnosis. In 21 
patients, the tumor was completely resected; in 30, the localized or regional 
tumor was grossly resected, and in 63 patients, grossly visible sarcoma was left 
behind. Sixteen patients (12%) had distant metastases at diagnosis. All patients 
were given multiagent chemotherapy and most received irradiation (XRT); none 
were treated with bone marrow transplantation.
RESULTS: One hundred seven patients (82%) achieved a complete response. At 10 
years, 62%, 61%, and 77% of the patients were alive after treatment on IRS-I, 
IRS-II, or IRS-III therapeutic protocols, respectively, similar to figures 
obtained in all IRS patients. At last follow-up evaluation, 42 patients had died 
of progressive tumor and one of infection. Survival at 10 years was most likely 
for patients with tumor that arose in the head and neck, extremities, and trunk, 
and for those who underwent grossly complete tumor removal before initiation of 
chemotherapy. For patients with localized, gross residual tumor, adding 
doxorubicin (DOX) to the combination of vincristine, dactinomycin, 
cyclophosphamide (VAC), and XRT did not significantly improve survival in 39 
patients (62% alive at 10 years) compared with that of 24 patients treated with 
VAC and XRT without DOX (65% alive at 10 years, P = .93).
CONCLUSION: This series indicated that EOE in children is similar to 
rhabdomyosarcoma (RMS) in its response to multimodal treatment. No benefit was 
apparent from the addition of DOX to VAC chemotherapy in patients with gross 
residual EOE.