[Chemotherapy in patients with refractory Ewing sarcoma]

Patients with metastatic, progressive or recurrent Ewing sarcoma have a poor prognosis. In addition to increasing the intensity of conventional chemotherapy, the combination of irinotecan and temozolomide has been proposed as an effective salvage regimen for some pediatric malignancies.

To evaluate the effect of two different salvage regimens on the final outcome of patients with refractory Ewing sarcoma.

During the period 2008-2012, twenty-two patients (age between 2.9 -19.3 years) with recurrent or refractory Ewing sarcoma were treated with the combination of vincristine, irinotecan and temozolomide (VIT regimen), and twenty patients were treated with the combination of cisplatin, doxorubicin, cyclophosphamide and teniposide (PACE regimen). All patients had standard tumour imaging and laboratory evaluation. All toxicities were documented. The WHO criteria were used to evaluate response. Statistical analysis was performed using STATA 10.0 for Windows. Results distributions were estimated using the method of Kaplan-Meier. The log-rang test was used to compare the groups.

A total of 91 cycles of VIT and 65 cycles of PACE were administered. For VIT therapy the overall response rate was 68.1%. Median time to progression was 3.0 months. Five patients are alive with no evidence of disease with a median follow-up of 10.3 months. For PACE therapy the overall response rate was 75%. Median time to progression was 3.5 months. Four patients are alive with no symptoms of disease with a median follow-up of 17.6 months. The 2 years overall survival probability after recurrence was 29.94%; no differences were detected between therapy groups. Toxicity for PACE was significantly higher.

The effectiveness of VIT regimen in refractory Ewing Sarcoma is comparable to conventional chemotherapy. The VIT regimen has less associated toxicities than the PACE regimen.