Curability in children suffering from malignant solid tumor is 50%. Thus, high dose chemotherapy with or without total body irradiation followed by autologous bone marrow transplantation (ABMT) has been proposed to patients suffering from cancer either at initial diagnosis (poor prognosis tumor) or at relapse. Thanks to these studies, drugs having dose effects properties have been selected. In some tumors, ABMT has significantly improved patients median survival. It remains to be determined if: 1. high dose chemotherapy protocols with ABMT are superior to new aggressive chemotherapeutic protocol without ABMT. 2. ABMT increases the curability of high risk patients.