Ewing sarcoma family of tumors.

The Ewing sarcoma family of tumors (ESFT) shares a common neural histogenesis, tumor genetics, and a fascinating biology, all of which hold the promise of identifying new therapeutic targets. The genetic hallmark of ESFT is the presence of the t(11;22)(q24;q12), which creates the EWS/FLI1 fusion gene and results in the expression of a chimeric protein. This article reviews much of the important work that has been reported over the past year regarding the biology and therapy of ESFT. Major studies include the observation that the early region (E1A) of human adenovirus type 5 is directly linked to and may initiate production of the EWS/FLI1 fusion transcript in normal human fibroblasts and keratinocytes. In addition, there is new information regarding the function of EWS/FLI1 and downstream signals by which it acts. New clinical information continues to support the addition of ifosfamide to standard chemotherapy regimens and help further refine prognostic features, including biologic features that may someday allow better risk stratification and therapy design.