It involves collecting safety and efficacy data, under the actual conditions of use of medicines in children and adolescents, using a validated tool (Ennov EDC) and relying on the network of Interregional pediatric oncology appeal organizations (RIOs) identified by INCa since 2010 and responsible for the organization of Pluridisciplinary Pediatric Interregional (RCPPI) and National Consultative Meetings which discuss each case of relapse in order to define the best therapeutic options.

The objective is to aim for completeness throughout the national territory. This is why this project will be carried out in close collaboration with the RIOs and RCPPI and that of the 31 centers of the SFCE which bring together more than 400 doctors pediatric oncologists and hematologists on the French territory

Inclusion Criteria:

• Age ≤ 25 years old at the time of inclusion in the study
• Patient with a pediatric tumor or leukemia in therapeutic failure or relapse without standard therapeutic options. Exceptionally, patients on the first line of treatment without standard therapeutic options may also be included (eg g: inoperable plexiform neurofibroma and MEK inhibitors, childhood fibrosarcoma and NTRK inhibitors).
• Patient not eligible for an early phase clinical trial open to inclusion on French territory or refusal of inclusion
• Patient treated with a new drug discussed at a RCPPI as part of a compassionate use issued by the ANSM or an off-label prescription of a drug of interest already authorized in adults.
• Patients treated in one of the SFCE centers authorized to prescribe chemotherapy
• Patient who did not object to participate after being informed of the study. The patient must be able and willing to cooperate in the study.

Exclusion Criteria:

• Patient included in an early phase clinical trial open to inclusions on French territory.
• Oral refusal to participate by the patient or their legal representatives, in reading the information note specific to the study
• Patient under guardianship or curatorship, deprived of liberty or in the impossibility of expressing opposition to participating in the study

Any child, adolescent or young adult, treated for a pediatric tumor or leukemia, in therapeutic failure or relapse without standard treatment option, not eligible / refusal of inclusion in a clinical study open on the territory and treated with an innovative drug within the framework of compassionate use or outside marketing authorization, in one of the centers of the SFCE (Société Française des Cancers de l' Enfant).