[Extra-pulmonary metastatic Ewing sarcoma: The French GroupOs diagnostic and therapeutic recommendations].

Patients who develop Ewing sarcoma with extra-pulmonary metastasis have a poor prognosis. A recent French protocol, CombinaiR3, was set up to evaluate the efficacy of induction chemotherapy followed by high-dose chemotherapy and metronomic maintenance treatment. It is now closed for inclusions and while waiting for the results, we propose a French consensus guideline for the management of patients diagnosed with Ewing sarcoma with extra-pulmonary dissemination. Main recommendations include induction chemotherapy with nine cycles of vincristine/doxorubicin/cyclophosphamide alternating with ifosfamide/etoposide. In case of insufficient response, other chemotherapy combination or inclusion in a clinical trial should be considered. Induction chemotherapy should be followed by local treatment, consisting of surgery and/or radiotherapy. Optimal local treatment is a milestone in the management of patients with Ewing sarcoma and should be discussed with experts and surgeons/radiotherapists working in the sarcoma network. High-dose chemotherapy (HDC) containing busulfan and melphalan followed by autologous stem-cell transplantation is still unclear, with contradictory results. HDC will then be discussed in national tumor board and administered to patients when compatible with local treatment. Given the high relapse rate observed among these metastatic patients, maintenance chemotherapy (so called metronomic regimen) will then be given for two years.