AMH as a Predictor of Infertility Risk in Children With Cancer (CHANCE)

In this clinical trial, we will prospectively evaluate the AMH (Antimüllerian Hormone) level before and after treatment (up to 18 years old) in a large cohort of pre- and post-pubertal children treated for cancer. The children enrolled are young patients between 3 and 14 year old who are newly diagnosed with cancer or benign diseases treated by chemotherapy and/or pelvic irradiation. They belong to one of these 3 groups (modified from Wallace et al, 2005): * High risk * Moderate/Low risk * No risk (control group) Primary endpoint: Evaluate AMH as a potential biomarker of ovarian reserve in prepubertal/pubertal girl treated by chemotherapy (classified according to the AAD(Alkylating Agent Dose) score) Secondary endpoints: * Evaluate the association between the post-treatment ovarian reserve and the AMH pretreatment values in patients considered as moderate or low risk. * Identify new patients group who may benefit from fertility preservation * Compare the gonadotoxicity of chemotherapy regimen according to the pubertal status. * Study the relation between the AMH levels and the pubertal age, menstruation cycle regularity, hormonal levels (FSH (follicle stimulating hormone), œstradiol, and testosterone) and bone age. Different parameters will be assessed at inclusion, end of the treatment and during the follow-up (every year during the first 3 years and then every 2 years until the end of the study) Oncological outcome The patients will be followed up for progression and survival as per standard local practice. Ovarian reserve and function: Ovarian reserve will be evaluated based on hormonal dosages at different times of the study: FSH, AMH, estradiol, testosterone and LH (luteinizing hormone). Menstrual function will be evaluated by collecting information of the pubertal status (spontaneous or induced puberty) and menstrual cycle characteristics Puberty evaluation: All children will have an evaluation of the TANNER pubertal stage at 9 years of age (or later if \> 9 years old at the time of inclusion) and once a year until the end of puberty (when patients reach Tanner stage 5). An X-ray of the left hand and wrist will be carried out for bone age evaluation at 9-11 and 13 years old.