The majority of patients were females, with a M:F ratio of 1:2.6. Males presented at a median age of 22.5 months (IQR 14.0 – 30.7 months) compared to females at 97 months (IQR 29.0 – 133.7 months). In the univariate analysis, sex was not a significant predictor of survival. However, in the multivariate analysis, females had a significantly lower risk of death (HR 0.284 p=0.037). To test the hypothesis that, among patients with MEGCTs, there existed a potential ‘threshold’ of age that characterised patients with worse outcomes, the models were refitted modelling age as a penalised-spline. Both the analyses conducted on OS and EFS suggested that, after controlling for all other potential confounding factors, age at diagnosis did not significantly affect the relative risk of death.