Ewing sarcoma-family tumors that arise after treatment of primary childhood cancer.

Abstract

Unlike osteosarcoma, the Ewing sarcoma family of tumors (ESFT) has rarely been reported as secondary malignant neoplasms after treatment of childhood cancer. ESFT arising as a second cancer was reviewed and characterized at our childhood cancer center. A retrospective review was undertaken of 11,183 patients age <21 years who were treated for a primary cancer between March 1962 and December 2003 at St. Jude Children's Research Hospital. All cases of ESFT were confirmed to have a rearranged EWS gene. Six cases of ESFT (1.3% of 479 second cancers) were identified in patients previously treated for lymphoma (n = 3), leukemia (n = 1), retinoblastoma (n = 1), or Wilms tumor (n = 1). None of these patients had a family history suggestive of a familial cancer syndrome. The median time between diagnosis of primary cancer and diagnosis of ESFT was 5.9 years (range, 3.1-18.3 years). ESFT occurred in typical anatomic locations: rib (n = 2), chest wall soft tissues (n = 2), pelvis (n = 1), and extremity (n = 1). One tumor arose at the margin of a previous radiotherapy field and 1 arose distant from previous radiotherapy fields; all other patients had not received radiotherapy. Three patients are alive at the time of this report, including 2 whose ESFT was diagnosed more than 8 years ago. ESFT occurs rarely after treatment of a primary cancer during childhood, and most cases do not appear to be related to radiation therapy. Long-term survival can be achieved in some patients, and therefore secondary ESFT should be treated with curative intent.