Analysis of prognostic factors in Ewing sarcoma using a population‐based cancer registry

BACKGROUND: Ewing sarcoma is a high-grade malignancy that most often occurs in children. Because its occurrence in adults has been historically low, few studies have been published on the epidemiology of Ewing sarcoma in this group of patients. By using data from a large, population-based cancer registry, the authors designed the present study to examine the outcome of children and adult patients with Ewing sarcoma and relevant prognostic factors. METHODS: A retrospective analysis of Ewing sarcoma patient cases in the California Cancer Registry database was performed to identify incident patient cases diagnosed between 1989-2007. Comparisons were made to examine differences in demographics, disease characteristics, treatment, and survival. Survival analyses were performed using Kaplan-Meier method with log-rank tests and Cox proportional hazards models. RESULTS: Seven hundred and twenty-five incident patient cases of Ewing sarcoma were identified, including 372 (51.3%) children and 353 (48.7%) adults. Hispanic race was associated with young age (P = .001) and lower socioeconomic status (SES; P = .0001). Pelvic involvement was associated with large tumor size (>8 cm; P < .0001), an increased incidence of metastasis (P < .0002), and poorer survival (P < .0001). After adjusting for clinically relevant factors, statistically significant decreased overall survival was seen with adults (hazard ratio HR, 1.71; 95% confidence interval CI, 1.35-2.17), Hispanics (HR, 1.33; 95% CI, 1.01-1.75), metastatic disease (HR, 2.74; 95% CI, 2.14-3.49), large tumor size (HR, 1.65; 95% CI, 1.17-2.34), no surgical treatment, and low SES. CONCLUSIONS: The authors determined that adult age, Hispanic race, metastatic disease, large tumor size, and low SES are poor prognostic factors for overall survival among Ewing sarcoma patient cases.