ABSTRACT
The majority of malignant diseases in children are sensitive to cytotoxic chemotherapy. This chemosensitivity is generally attributed to the quickly proliferating character of these tumours and to their capacity to enter apoptosis. Chemotherapy has a major place in the treatment of paediatric cancers and contributes for a large part, to the current therapeutic successes. 75% of children can be cured with current chemotherapy. This raises the question of its long term toxicity and late effects in adults who recovered from a cancer during their childhood. This equally raises the issue of refractory malignant diseases (certain brain tumours, several metastatic diseases, high-risk leukaemias and some rare or complex mesenchymal tumours). Indeed, malignancy remains a major cause of death in children. There is an urgent need to better understand the biology of these refractory tumours and to develop new active treatments.
