Treatment of Ewing sarcoma family of tumors with a modified P6 protocol in children and adolescents

Background Reported overall survival (OS) rates of patients with localized Ewing sarcoma family of tumors (ESFT) are >80% when treated with the MSKCC P6 protocol. However, it has been associated with a 5.8% incidence of secondary leukemias. A modified P6 (mP6) protocol with reduced exposure to chemotherapy is presented. Procedure Thirty‐one newly diagnosed ESFT patients were enrolled onto this phase II, single‐arm, non‐randomized protocol. Courses 1, 2 and 4 consisted of cyclophosphamide 4.2 g/m2, doxorubicin 75 mg/m2, and vincristine 2 mg/m2 (CDV). Cycles 3 and 5 consisted of ifosfamide 9 g/m2 and etoposide 500 mg/m2 (IE). Course 5 ifosfamide was 14 g/m2 if necrosis was