Extra-osseous Ewing sarcoma.
BACKGROUND
Clinical data and data on outcome of extra-osseous Ewing tumors are scarce.


METHODS
After a search for Ewing tumors in the database of a single institution over a period of 20 years, 16 out of 192 cases were found to have extra-osseous primary tumors.


RESULTS
Ages at initial diagnosis ranged from 2.5 to 17 years. Follow-up period ranged from 4 months to 24.8 years (mean 8.4 years). Eleven patients were treated according to protocols for Ewing tumors, while in 4 cases soft tissue protocols were used. In a single patient only surgery was done. Two patients had progressive disease despite chemotherapy; a third patient had only tumor response on the initial 2 chemotherapy courses. All 3 patients with initially metastatic disease died. One patient developed a second malignancy. Overall survival at 5 years was 75%. Event-free survival (EFS) at 5 years was 68%; for nonmetastatic patients 5-year EFS was 83%.


CONCLUSIONS
The authors conclude that nonmetastasized extra-osseous Ewing tumors have a prognosis at least similar to that of osseous Ewing tumors.
Department of Paediatric Oncology, Emma Children Hospital AMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. h.vandenberg@amc.uva.nl
Hendrik
H
van den Berg
Richard C
RC
Heinen
Heleen J
HJ
van der Pal
Johannes H M
JH
Merks
D000293:Adolescent; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D003609:Dactinomycin / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007069:Ifosfamide / Q000627:therapeutic use; D053208:Kaplan-Meier Estimate; D008297:Male; D011379:Prognosis; D011500:Protein Synthesis Inhibitors / Q000627:therapeutic use; D012512:Sarcoma, Ewing / Q000188:drug therapy* / Q000401:mortality*; D016896:Treatment Outcome; D014750:Vincristine / Q000627:therapeutic use
D018906:Antineoplastic Agents, Alkylating; D000972:Antineoplastic Agents, Phytogenic; D011500:Protein Synthesis Inhibitors; D003609:Dactinomycin; D014750:Vincristine; D007069:Ifosfamide