[Fertility preservation in adolescents and young adults with cancer]

Fertility impairment due to treatments is a major concern for patients who have survived cancer in adolescence or as a young adult. The impact of cancer treatments on fertility depends on the age at treatments, types and cumulative doses of chemotherapy, radiation doses to organs at risk, and on surgeries conducted. Fertility preservation strategies have been developed for many years, and recently diversified thanks to advances in reproductive biology. In female adolescents and young adults, ovarian stimulation followed by oocyte (or embryo) vitrification, ovarian tissue cryopreservation, and sometimes oocyte vitrification after in vitro maturation are options that can be discussed. In some diseases, potential risk of residual disease in cryopreserved ovarian cortex has to be taken into account before ovarian tissue transplantation, which should always be discussed with the oncological team. The use of GnRH agonists for fertility preservation remains controversial. In case of pelvic radiation therapy, intensity-modulated conformal radiotherapy, and ovarian transposition can preserve organs at risk. In male adolescents and young adults, sperm crypopreservation is an established fertility preservation method, which can in most cases, including adolescents, be carried out. In prepubertal or peripubertal patients, testicular tissue cryopreservation can be proposed. Information on the effects of treatments and discussion of fertility preservation options should be systematic in adolescents and young adults with cancer.