Second malignancies in patients treated for Ewing sarcoma: A systematic review.

The therapies used to treat Ewing sarcoma are associated with a risk of second malignant neoplasm (SMN). We conducted a systematic review to pool available evidence on the risks, types, and outcomes after SMN. We obtained 52 articles that met inclusion criteria. Cumulative incidence rates of SMN ranged from 0.9 to 8.4% and 10.1 to 20.5% at 5 and 30 years after initial diagnosis. Of the 327 reported SMNs, 63.6% were solid tumors, although acute myeloid leukemia /myelodysplastic syndrome was the single most commonly diagnosed SMN, with generally poor outcomes. Patients treated for Ewing sarcoma are at substantial risk of SMN, with a broad range of reported secondary cancers.