[Gonadal toxicity of cancer therapies in children].

Numerous cytotoxic drugs used to treat childhood cancers, as well as pelvic or hypothalamo- pituitary irradiation and gonadal surgery, can affect subsequent hormonal function and fertility. Prevention of these adverse consequences is based primarily on therapeutic de-escalation when possible, and now also on gonad or gamete preservation. These patients and their parents must receive thorough information, taking into account the child's age, the proposed treatments, and the length of follow-up. Teams treating childhood cancers must receive appropriate training, and access to innovative fertility-preserving techniques must be guaranteed at the national level.