Shi J, et al. - This study is to determine the risk factors for metastasis of Ewing sarcoma (ES) patients in the surveillance, epidemiology, and end results (SEER) database. Researchers obtained clinicopathological data of Ewing sarcoma (ES) individuals in the SEER database and then applied chi-square test and logistic regression to ascertain risk factors associated with metastasis. They further performed survival analysis involving Kaplan-Meier curve and Cox proportional hazard model to explore the risk factors associated with overall survival and cancer-specific survival and then developed the nomogram to visualize and quantify the probability of survival. The results showed that tumor size and primary site were associated with distant metastasis at diagnosis. Age, tumor size, primary site, tumor extent, and chemotherapy were significantly correlated with overall survival and cancer-specific survival. Nomograms could prognosticate the probability of OS and CSS and displayed good consistency with actual observed outcomes internally and externally.