Ewing Sarcoma in the Pediatric Population: Predictors of Survival Within the United States.

Introduction: Bone and joint tumors are the third most common cause of pediatric cancer-related deaths in the United States. Although there have been improvements in survival rates among pediatric cancer patients over the past few decades, bone and joint cancers remain the exception. Considering current clinical trials involving novel targeted therapies, the establishment of updated mortality rates and predictors of survival for this cancer would be prudent. This investigation sought to determine updated 5-year survival rates and predictors of survival among pediatric Ewing sarcoma (ES) of bone treated within the United States.

Methods: The National Cancer Database was retrospectively inquired for all pediatric ES cases within the most updated bone and joint public use file available in September 2022. The reported data were truncated to only include patients with reported 5-year vital (ie, survival) status. Cox proportional hazard regression was conducted on both the truncated data and the entire cohort to validate the findings. The patients were then separated into alive versus deceased cohorts, and univariate regression analysis was done followed by multivariable regression of notable variables of interest.

Results: Overall, an aggregated 5-year survival rate of 74.5% was found in the included patient cohort. Patients with localized cancer had a comparatively improved 5-year survival rate of 84.70% as opposed to those with macrometastatic disease on presentation with a survival rate of 50.4%. Patient demographic-, tumor-, and treatment-specific variables all demonstrated an effect on survival. The multivariable predictors of worse mortality were found to include older age, larger tumor size (>8 cm), macrometastatic disease on presentation, and positive surgical margins.

Conclusion: This analysis serves to establish updated survival rates of pediatric ES treated within the United States to set standards for comparison among future studies. Continued multi-institutional and international collaboration is needed to optimize current treatment results and develop novel targeted therapies.