Clinicodemographic characteristics of extraosseous Ewing sarcoma: A comparative meta-analysis of pediatric and adult patients

Background: Evidence suggests different presentation patterns and prognosis of extraosseous Ewing Sarcoma (EES) based on age. Thus, we carried out this study to test the difference between children and adult EES cases regarding clinicodemographic characteristics and prognosis. Methods: A total of 4 databases were explored yielding 18 relevant studies for data synthesis. Outcomes included the comparison of demographic and clinical characteristics as well as prognosis between children and adults with EES. Log odds ratio (logOR) and its 95% confidence interval (CI) were pooled across studies. Statistical models/methods were selected based on heterogeneity. Results: Our analysis included a total of 1261 children and 1256 adults. When we compared these two age categories, we did not observe a significant difference in the risk of developing EES [logOR = -0.13; 95% CI: -0.65: 0.39; I2 = 88.42%]. No significant differences regarding gender, tumor location, and size (≤5 vs. >5 cm), EWSR1 positivity, or management modality. We did not observe significant difference regarding clinical outcomes, such as 5-year overall survival and event-free survival, recurrence, mortality, no evidence of disease, and secondary metastasis. Conclusions: Our findings highlight the absence of an association between the age category of patients and the incidence of EES, as well as its clinical outcomes.