Background: The rarity of malignant and intermediate vascular tumors in children means that little is known about their clinical course, optimal treatment, and variables predicting survival.
Methods: A total of 32 children with malignant vascular tumors (14 angiosarcomas [AS], 5 epithelioid hemangioendotheliomas, and 13 intermediate vascular tumors, including other hemangioendotheliomas plus adult-type hemangiopericytomas), registered in the German and Polish Paediatric Soft Tissue Sarcomas Study Groups, were treated following the Cooperative Weichteilsarkom Studiengruppe (CWS)-81, -86, -91, and -96 protocols.
Results: Male sex, AS histology, tumor size >5 cm, and T2 invasiveness were independent predictors of inferior 5-year overall survival, while AS histology and T2 invasiveness were predictors of inferior 5-year event-free survival. AS histology was the most important negative prognostic factor for overall survival and event-free survival. Completeness of primary tumor excision was a good prognostic factor for survival in univariate, but not multivariate, analysis. Local therapy (radiotherapy and delayed surgery) were provided to the minority of patients (28% and 38%, respectively) late in the course of disease (after a mean of 9 and 6 months, respectively) and did not prevent local relapses. Response to systemic treatment was poor (44%) and did not prevent local and distant relapses.
Conclusions: The clinical course and outcome in childhood epithelioid HE seems to be similar to intravascular tumors and less aggressive than AS. RTX and delayed surgery should be performed more frequently and earlier in the disease course. An urgent need for modification of systemic therapy is needed because of the development of many metastatic and/or combined relapses and poor response to classic chemotherapy. The problem of effective therapy for childhood AS is the most appaling: 13 of 14 patients died of progression despite multimodal treatment.