Tumor size and metastases are known risk factors in Ewing tumors. Adequate staging is essential to stratify treatment intensity, but TNM staging is not established.

The validity of TNM staging was tested based on tumor volume (T1 ≤200 ml; T2 > 200 ml ≤500 ml; T3, > 500 ml), the presence or absence of lymph node metastases (N0, N1), and distant metastases (M0, no metastases; M1 lung/pleura metastases; M1a ≤5 nodules; M1b > 5 lesions; M2 bone metastases; M2a, 1 lesion; M2b > 1 lesion and/or microscopic bone marrow contamination; M3, multi-system metastases). 1799 Ewing sarcoma patients of the (EI)CESS/EE99 studies entered into the Muenster database from 1981–2008 were analyzed.

Ten-year event-free survival (EFS) was 0.46. EFS in patients without metastases (T1-3N0M0) was 0.56 compared to 0.22 in metastatic patients (T1-3N0,1M1-3), p< .0001. In non-metastatic patients, tumor volume discriminated EFS: T1:0.62; T2:0.43; T3:0.40, p< .0001. The rare event of lymph node metastases correlated with unfavorable prognosis (N0:0.47, N1:0.12, p< .0001). The difference in EFS between pulmonary, skeletal and multi-system dissemination was significant: M1:0.29, M2:0.23; M3:0.12, p< .0001. The discrimination of M1 subgroups (M1a/M1b) was of prognostic relevance (p=.0050); M2 subgroups (M2a/M2b) discriminated outcome less clearly (p=.0457).

TNM staging is appropriate in Ewing tumors and should be incorporated in future trials.

Background: Intensive chemotherapy in sarcoma treatment may lead to weight loss, and in turn reduce dose intensity. A possible correlation between weight loss under treatment and outcome has never been analysed in sarcoma treatment. Ewing sarcoma (ES) patients undergoing intensive non-corticosteroid-containing chemotherapy commonly experience weight loss. The German Paediatric Oncology/Haematology Society (GPOH) Ewing sarcoma trials (CESS, EICESS) registry was analysed with respect to weight loss and outcome.

Patients and Methods: Body weight (BW) both at diagnosis and after a median of 12 courses of chemotherapy was available in 837 of 1549 ES patients, excluding amputees. Changes in BW were calculated as percentage of initial BW; outcome was determined as event-free-survival (EFS) from diagnosis according to Kaplan-Meier. Correlations of BW and outcome and potential confounders like disease stage or tumour volume were estimated uni- and multivariately.

Results: Weight loss was not correlated with inferior outcome: A loss of 10%–20% of BW was associated with a slightly more favourable outcome (3-year EFS 0.64 +/−0.106, N=82) than weight gain of 10%–20% of BW (3-year EFS 0.58 +/−0.098, N=97), p=0.101. Multivariate analyses revealed no confounders interfering with these results.

Conclusions: In 837 ES-patients analysed, weight loss did not correlate with inferior outcome. This should be observed in discussions about tube feeding and/or parenteral nutrition under cytostatic therapy. Future analyses of the prognostic impact of extreme under- or overweight both at diagnosis or under treatment are warranted in order to develop appropriate guidelines. Validity of this observation should be analysed for other solid tumours.

Supported by EC Biomed and Deutsche Krebshilfe