Extraosseous Ewing sarcoma in children and adolescents: A retrospective series from a referral pediatric oncology center

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.

Extraosseous Ewing Sarcoma in Children: A Systematic Review and Meta-Analysis of Clinicodemographic Characteristics

Background: We conducted this systematic review to provide comprehensive evidence on the prevalence, clinical features and outcomes of young extraosseous Ewing sarcoma (EES) cases. Methods: PubMed, Scopus, Web of Science, and Google Scholar were searched for articles reporting the occurrence of EES among children and adolescents (<21 years). The primary outcome included the rate of occurrence of EES among children and adolescents, while the secondary outcomes included the descriptive analyses of the demographic characteristics, tumor characteristics, and clinical outcomes of the affected cases. The data are reported as the effect size (ES) and its corresponding 95% confidence interval (CI). Results: A total of 29 studies were included. Twenty-four reported instances of childhood disease among all the EES cases [ES = 30%; 95%CI: 29−31%], while five studies reported extraosseous cases among the pediatric EES cases [ES = 22%; 95%CI: 13−31%]. The thorax is the most common location of childhood EES [33%; 95%CI: 20−46%] followed by the extremities [31%; 95%CI: 22−40%]. Concurrent chemotherapy and radiotherapy [57%; 95%CI: 25−84%] was the most commonly implemented management protocol in the pediatric EES cases. The rate of no evidence of disease and 5-year overall survival was 69% for both outcomes. Mortality occurred in 29% of cases, while recurrence and secondary metastasis occurred in 35% and 16% of cases, respectively. Conclusions: Our findings provide insight into the clinical features and outcomes of EES among children and adolescents.