Ethnic and racial differences in patients with Ewing sarcoma

BACKGROUND: Ewing sarcoma (ES) was a malignant tumor of bone or soft tissue. One of the few risk factors for developing ES is race, with a higher incidence noted in populations of European rather than African or Asian ancestry. The goal of the current study was to evaluate racial and ethnic differences in presentation and overall survival (OS) among patients diagnosed with ES before age 40 years. METHODS: Data from the Surveillance, Epidemiology, and End Results database identified 1715 patients aged <40 years who were diagnosed with ES between 1973 and 2005. Racial and ethnic group differences were compared using chi-square tests. OS was estimated by Kaplan-Meier analysis and compared using log-rank tests and Cox models. RESULTS: Black patients had significantly more soft-tissue tumors compared with white non-Hispanic patients (P <.0001). Asian and white Hispanic patients were found to have an intermediate frequency of soft-tissue tumors that also differed from white non-Hispanic patients (P <.0001). White Hispanic patients presented with a higher proportion of larger tumors compared with white non-Hispanic patients (P = .042). Black patients tended to be older than white non-Hispanic patients (P = .012). Sex, frequency of pelvic tumors, and metastatic status did not appear to differ by ethnicity or race. OS was found to differ according to race and ethnicity. Even after controlling for known confounders, OS was significantly worse for black, Asian, and white Hispanic patients compared with white non-Hispanic patients (P = .0031, P = .0182, and P = .0051, respectively). CONCLUSIONS: Ethnic and racial differences in characteristics and outcomes of patients with ES do exist. Understanding the etiology of these differences will require further study.