Survival and treatment in older patients with ewing sarcoma: an analysis of the national cancer database

Ewing sarcoma (EWS) is a malignancy which primarily arises in adolescence and has been studied extensively in this population. Much less is known about the rare patient cohort over the age of 40 at diagnosis. In this study, we describe the survival outcomes and clinical characteristics of this population.

This retrospective cohort study utilized the National Cancer Database (NCDB) to identify 4600 patients diagnosed between 2004 through 2019. Of these patients, 4058 were under the age of 40 and 542 were over 40. Propensity score 1:1 matching was performed according to sex and race. Univariate and multivariate logistic regression was performed to generate odds ratios (OR) and a Multivariate Cox regression model was used to generate a hazard ratio (HR) for patients over 40. Kaplan-Meier curves were used to estimate survival from diagnosis to death between age groups. Chi-square tests were used to compare demographic and socioeconomic patient characteristics. IBM statistics version 27.0 was used. p < 0.05 was used to indicate statistical significance.

EWS patients older than 40 experienced worse survival outcomes compared to patients under the age of 40. 5-year survival was 44.6% for older patients vs. 61.8% for younger patients (p < 0.05). A multivariate Cox proportional hazards model showed that age was independently associated with inferior survival. (HR 1.96; p < 0.05). EWS patients over the age of 40 were more likely to have tumors originating from the vertebral column (16.1% vs 8.9%; p < 0.05) and cranium (5.3% vs. 2.9%; p < 0.05) and had a higher rate of axial tumors (31.6% vs. 18.5%; p < 0.05) compared to patients under 40. Additionally, patients older than 40 experienced a significantly longer delay between the date of diagnosis and initiation of systemic treatment (36.7 days vs. 24.8 days; p < 0.05) and were less likely to receive adjuvant chemotherapy (93.4% vs. 97.9%; p < 0.05).

An age over 40 is associated with decreased survival for patients with EWS. Due to the rarity of EWS in this cohort, the optimal role of systemic treatment remains unknown and has yet to be clearly elucidated. Consequently, our findings suggest that older patients receive disparities in treatment which may be contributing to decreased survival rates.