Response to high-dose ifosfamide in patients with advanced/recurrent ewing sarcoma

Aim. To determine activity and toxicity of high-dose ifosfamide (HDIFO) in recurrent or advanced Ewing sarcoma family tumors (EFT). Methods. Thirty-seven EFT patients [median age 17 years (645 years)] previously treated with chemotherapy regimens including standard dose ifosfamide were enrolled. HDIFO was administered for metastatic recurrent disease in 33 patients and for progression during neoadjuvant chemotherapy in 4 patients. All patients who received two courses of 15 g/m² ifosfamide were evaluable for radiographic response assessed according to RECIST criteria. Results. Transient Grade 4 neutropenia and thrombocytopenia in 97% and 54% HDIFO courses respectively and severe CNS toxicity in one patient were observed. Thirty-five patients were evaluable: 12 (34%) had complete (2) or partial (10) response, 11 (32%) had stable disease, and 12 (34%) had progression. Conclusions. In patients with relapsed or advanced EFT previously treated with standard dose ifosfamide HDIFO is active and it should be considered a treatment option.