Maintenance treatment with trofosfamide in patients with primary bone ewing sarcoma - single center experience

Background: Patients with Ewing sarcoma have a dismal outcome. Maintenance treatment with trofosfamide has been proposed as an effective regimen for some paediatric malignancies. Aim: We sought to evaluate the schedule of trofosfamide for patients with high-risk primary bone Ewing sarcoma.

Materials and methods: Fifteen patients with primary bone Ewing sarcoma received treatment with trofosfamide (150 mg/m2 p.o. days 1-10) every 28 days. All patients had standard tumour imaging and laboratory evaluation. All toxicities were documented.

Results: A total of 90 cycles (median 5 cycles/patient) were administered. A complete response was maintained in nine patients, while six patients had disease progression during treatment. Median time to progression was 1.9 months (range 1.8 to 4.6). Eleven patients (73.3%) are alive including nine with no evidence of disease with a median follow-up of 3.9 years (range 1.4 to 7.6). All patients with active disease at the start of the trofosfamide treatment died. There were no significant toxicities.

Conclusions: Treatment with trofosfamide is well-tolerated and could have a role to maintain response in patients with primary bone Ewing sarcoma. Further studies are needed to better define the use of this regimen in the upfront management of those patients.