To assess the neurocognitive outcomes in patients treated with chemotherapy for a malignant bone tumor during childhood and adolescence and the factors associated with neurocognitive impairment and/or complaints

Inclusion Criteria:

For study OSE A and B

• Patients treated for a bone sarcoma: Ewing or osteosarcoma
• Age under 19 years at initial diagnosis
• Treated in the Pediatric Oncology Department of Gustave

For patients diagnosed between 01.01.2001 and 31.12.2010: patients alive in complete remission at least 5 years after diagnosis

• Treated with at least one course of HDMTX for osteosarcoma
• Treated without HDMTX for Ewing sarcoma
• Time interval between the end of treatment and inclusion >10 y
• Age > 21 y at inclusion
• Patients with informed consent signed
• Patient under guardianship
• Affiliated to French health insurance or beneficiary of the same or equivalent

For study OSE- B only:

• Treated with at least 8 courses of HDMTX for osteosarcoma
• Treated without HDMTX for Ewing sarcoma
• Patients with Ewing sarcoma will have to be matched with osteosarcoma patients according to age at the time of treatment, sex, and duration of follow-up
• School level equivalent of at least the end of primary school

Exclusion Criteria:

For study OSE A and B

• Brain radiotherapy
• Previous relapse except those treated by local treatment without any chemotherapy
• Second malignancy treated with chemotherapy
• High dose chemotherapy with stem cell support
• Non-French speaking patients
• Pregnant and breastfeeding women

For study OSE- B only:

- Patient deprived of his liberty by a judicial or administrative decision