Tandem high-dose chemotherapy strategy as first-line treatment of primary disseminated multifocal Ewing sarcomas in children, adolescents and young adults

The prognosis of primary disseminated multifocal metastatic Ewing's sarcoma (PDMES) is poor even if a slight improvement has been achieved with high-dose alkylating agent-containing chemotherapy. To enhance treatment efficacy, we assessed the feasibility, safety and efficacy of a tandem high-dose chemotherapy (HDC) regimen. In a single institution, patients with PDMES received six courses of vincristine/ifosfamide/doxorubicin/etoposide induction therapy, followed by high-dose thiotepa, and then melphalan-busulfan, 8 weeks apart. Surgical resection of primary tumour was carried out between the two HDC regimens and 70 days after the last HDC regimen for post-operative radiotherapy or irradiation alone. From October 2002 to 2009, 13 of the 18 consecutive patients with PDMES (72%) received the full treatment programme. The other five patients experienced early progression and died. Among the 13 patients, 11 relapsed after the end of the treatment programme within 6 months (2.2-11.9) from end of therapy. Only two patients are still alive in first complete remission after 9 years. The 3-year event-free survival (EFS) and overall survival (OS) rates were 11 and 22%, respectively. The median EFS and OS duration from the diagnosis were 13.4 and 17.3 months, respectively. Neither major complications nor treatment-related death occurred. The tandem-HDC regimen was feasible, with expected side effects, but it did not improve the outcome of patients with PDMES.