[Fertility preservation in adolescent cancer patients].

Recent advances in cancer therapy have improved the survival rate of infant and adolescent facing cancers. The objective of treatment is not only to cure cancer but also to limit its secondary consequences. Impaired fertility is an important sequel of numerous treatments against cancer. Therefore, efforts to maintain fertility must be a major consideration in the treatment plan. This review focuses on various options for preserving fertility in adolescents. In female patients, ovarian transposition out of the radiation field may considerably reduce the radiation received by the ovaries. The benefits of GnRH analogue are not yet clear and apoptosis inhibiting agents are unavailable. Embryo freezing is the most reliable method to preserve fertility. This method is time-intensive, requires a partner, and ovarian stimulation may not always be compatible with the need of starting treatment against cancer immediately. Oocyte cryopreservation is an experimental technique that can be used in post-pubertal patients irrespective of their marital status. The cryopreservation of mature oocytes has similar constrains as embryo freezing ; in addition the technique is not as well-established and the pregnancy rates obtained are much lower than those achieved with embryos. Freezing of immature oocytes followed by in vitro maturation in spite of its theoretical advantages is inefficient in current practice. Ovarian tissue cryopreservation offers great hope because it has the potential to preserve a large number of primordial follicles without any ovarian stimulation and preliminary trials have shown some success. For male adolescents cancer patients semen cryopreservation is a successful alternative that should be offered systematically when cancer therapies that may impair gonadal function are indicated. For prepubertal males there is presently no standardized technique for preserving fertility ; however, the development of testicular germ-cell harvest needs to be considered.