Ewing sarcoma family tumors (ESFT) as second malignant neoplasms (SMN) following treatment of a primary malignant neoplasm (PMN) during childhood

Abstract

8539 Background: ESFT comprise approximately 2% of malignancies in childhood. Although there are scattered reports in the literature of ESFT as a SMN, the proportion of SMN that are ESFT is unknown. Methods: We reviewed our institutional experience from 3/62 to 12/03 with ESFT arising as a SMN. Demographic data, diagnostic and treatment information for both the PMN and SMN, and outcome data were recorded. Results: Of the 431 patients with 2 or more malignancies, 8 (1.9%) had ESFT as a SMN. The median age at diagnosis of PMN was 4.2 years (range, 0.8–12.5 years), and of ESFT was 13.4 years (range, 4.9–22.0 years). Five patients were female and 7 were white. The PMN was retinoblastoma (n=3), Wilms tumor (n=2), acute lymphoblastic leukemia, Hodgkin lymphoma, and non-Hodgkin lymphoma (n=1 each). Six patients received chemotherapy for treatment of the PMN including alkylating agents (n=3), anthracyclines (n=6), and etoposide (n=1). Four also received radiotherapy (RT) for the PMN (dose range, 10.8–48 Gy, median 30 Gy). The median latency between the PMN and ESFT was 6.3 years (range, 3.1–18.3 years). The ESFT primary sites were chest wall/rib (n=4), extremity (n=3) and pelvis (n=1). Three patients had metastases at presentation. Among the 4 patients who had received RT previously, 2 ESFT arose outside the field and 2 arose at the field margins. Four patients have died: 3 due to progressive ESFT and 1 due to a third malignancy (osteosarcoma arising within the RT field used to treat the ESFT). The 5-year estimated survival following the development of ESFT was 57.1%±16.7%. Conclusions: The proportion of ESFT as a SMN following treatment of childhood cancer is similar to the proportion of ESFT as a PMN in childhood. Patients with retinoblastoma may be at higher risk than other childhood cancer survivors for secondary ESFT. Most secondary ESFT are not radiation-induced. Survival appears to be only slightly inferior to that of de novo ESFT. No significant financial relationships to disclose.