Autor:innen:
V. Rechl (Essen, DE)
A. Ranft (Essen, DE)
V. Bhadri (Camperdown, AU)
B. Brichard (Brüssel, BE)
S. Collaud (Essen, DE)
S. Cyprova (Prag, CZ)
H. Eich (Münster, DE)
T. Ek (Göteborg, SE)
H. Gelderblom (Leiden, NL)
J. Hardes (Essen, DE)
L. Haveman (Utrecht, NL)
W. Hartmann (Münster, DE)
P. Hauser (Miskolc, HU)
H. Jürgens (Münster, DE)
J. Kanerva (Helsinki, FI)
T. Kühne (Basel, CH)
A. Raciborska (Warschau, PL)
J. Rascon (Vilnius, LT)
A. Streitbürger (Essen, DE)
B. Timmermann (Essen, DE)
Y. Uhlenbruch (Bochum, DE)
J. Kersting (Essen, DE)
U. Dirksen (Essen, DE)
Introduction: Ewing Sarcoma (EWS) is a rare and highly malignant bone tumor and represents the second most common bone tumor in children and adolescents following osteosarcomas. Pelvis and extremities are the most common sites for the EWS to arise while the sacrum as primary is very rare. Local therapy is challenging especially for sacral EWS due to its anatomical location and studies focusing on this site are scarcely available. Patients and Methods: To analyze prognostic factors we retrospectively analyzed databases of EURO-E.W.I.N.G. 99 and EWING 2008. Both clinical trials included 124 patients (pts) with localized (n=70) or metastasized (n=53) sacral EWS. All pts received systemic treatment according to the protocols. For local control 64.3% received definitive radiotherapy (followed by combined modality treatment (25.2%) and surgery alone (4.3%). Some pts had no local treatment (6.1%) mainly due to early relapse. The study endpoint was event free survival (EFS). Factors probably associated with survival e.g., age, sex, tumor volume, local treatment modality and applied study protocol were included in the univariate and multivariable analyses. Results: Age under 18 years was associated with better outcome (3y-EFS: .45 vs .12; P=.03) in patients with metastases at diagnosis. In general, metastases at diagnosis (3y-EFS: .33 vs .68; P < .001; HR=3.4, 95% CI 1.7 to 6.6), large tumor volume (3y-EFS: .36 vs .69; P=.002; HR=2.1, 95% CI 1.1 to 4.0) or age ≥ 18 years (3y-EFS: .41 vs .60; P=.10; HR=2.6, 95% CI 1.3 to 5.2) were associated with dismal outcome. Interaction was seen in patients with definitive radiotherapy compared to other patients by a higher EFS in localized disease in contrast to a lower EFS in metastatic patients (P < .001) . Conclusions: Young age is associated with a better outcome, and interaction was observed between definitive radiotherapy and metastases at diagnosis. Regarding local therapy modality, the anatomical location is decisive and the majority of pts received definitive radiotherapy.