Abstract 123P
Background
Although there are several prognostic factors for patients with Ewing sarcoma (ES), but so far they have not been implemented in decision-making in routine practice. The aim of our study was to build a prognostic model for overall survival (OS) after potentially curative treatment in patients with locally advanced ES.
Methods
We analyzed data on 256 consecutive nonmetastic patients ≤25 years of age treated between 1998 and 2018 in Mother and Child Institute, Warsaw (n=192) and Maria Sklodowska-Curie National Research Institute of Oncology in Warsaw (n=64). Training set (n=188) was used to identify independent prognostic factors for OS with the Kaplan-Meier estimator, log-rank test, and the multivariate Cox model. Identified factors were used to prepare the nomogram, which was then validated in the validation set (n=65), intended proportion was 75:25, using random sampling stratified on local surgical treatment (radical resection, non-radical resection, inoperable).
Results
First, the results of multivariate Cox regression used to create the nomogram showed that age, pathologic fracture, type of induction systemic chemotherapy (VIDE vs other), type of local treatment (radiotherapy+surgery vs surgery only vs radiotherapy only), and the time of diagnosis were independent prognostic factors. Pathological fracture (HR 4.62, 95% CI 1.81–11.80), and lack of possibility of radical local treatment after the induction therapy (6.10, 95%CI 1.93 – 19.30) were negative prognostic factors. The prognosis improved significantly with the time of diagnosis, by 8% per year (HR 0.92, 95% CI 0.87-0.97). Age 10 years or less at diagnosis and receiving VIDE as an induction therapy regimen tended to predict better OS. Then we confirmed that an assessment of model calibration showed that the nomogram has a good agreement for the patients survival at selected time points (24 and 60 months). The Harrell’s concordance index on the training dataset was 0.78 (95%CI 0.72-0.84) and on the validation dataset - 0.69 (95% CI 0.56–0.83).
Conclusions
Our nomogram has a significant predictive power and could be helpful for assessment of the risk among ES patients and guide treatment decision. Nevertheless, it should be further validated in other datasets.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.
Funding
Has not received any funding.
Disclosure
P. Rutkowski: Financial Interests, Personal, Invited Speaker, honoraria for lectures: MSD, BMS, Pierre Fabre; Financial Interests, Personal, Advisory Board: MSD, BMS, Pierre Fabre, Merck, Sanofi, Blueprint Medicines, Philogen; Financial Interests, Personal, Invited Speaker: Merck, Sanofi, Novartis, AstraZeneca; Financial Interests, Institutional, Research Grant, research grant for ISS: Pfizer; Financial Interests, Institutional, Funding, research grant for institution: BMS; Non-Financial Interests, Personal, Member of Board of Directors: Polish Society of Surgical Oncology; Non-Financial Interests, Personal, Member of Board of Directors, President: Polish Oncological Society. P. Sobczuk: Financial Interests, Personal, Other, Travel grant: Novartis; Financial Interests, Personal, Other, Travel Grant: MSD, BMS; Financial Interests, Personal, Invited Speaker: Swixx BioPharma, BMS, Gilead; Financial Interests, Personal, Advisory Board: Sandoz; Financial Interests, Personal, Stocks/Shares: CelonPharma; Non-Financial Interests, Institutional, Product Samples: Immutep; Non-Financial Interests, Personal, Leadership Role, Board Member, Chair of Young Oncologists Section: Polish Society of Clinical Oncology. K. Kozak: Financial Interests, Personal, Invited Speaker: Bristol Myers Squib, MSD, Novartis, Pierre Fabre, Sanofi. I. Lugowska: Financial Interests, Personal, Invited Speaker: Roche, ESMO; Financial Interests, Institutional, Other, Research grants: Roche; Financial Interests, Institutional, Other, Research grant: Agenus; Financial Interests, Personal and Institutional, Invited Speaker: MSD, Roche, BMS, Janssen, AstraZeneca, Amgen, RyVu, Incyte, Siropa, Mennarini, Celon, Pfizer, Agenus, Rhizen; Non-Financial Interests, Personal, Project Lead: MSCI; Non-Financial Interests, Personal, Other, Board Member: OECI; Other, Personal, Other, Robert Lugowski (my husband) co-ownership: Clininote. All other authors have declared no conflicts of interest.