Male fertility following childhood cancer: current concepts and future therapies.

Prepubertal boys treated for cancer may exhibit impaired fertility in later life. A number of chemotherapeutic agents have been identified as being gonadotoxic, and certain treatment regimens, such as that used for Hodgkin's disease, are particularly associated with subsequent infertility. Radiotherapy may also cause gonadal damage, most notably following direct testicular irradiation or total body irradiation. Because of the varied nature of the cytotoxic insult, it can be difficult to predict the likelihood of infertility in later life. Currently it is not possible to detect gonadal damage early due to the lack of a sensitive marker of gonadal function in the prepubertal age group. Semen cryopreservation is currently the only method of preserving fertility in patients receiving gonadotoxic therapy. This is only applicable to postpubertal patients and can be problematic in the adolescent age group. At present there is no provision for the prepubertal boy, although there are a number of experimental methods currently being investigated. By harvesting testicular tissue prior to gonadotoxic therapy, restoration of fertility could be achieved following treatment, either by germ cell transplantation or by in vitro maturation of the germ cells harvested. Alternatively, rendering the testes quiescent during cytotoxic treatment may protect the germ cells from subsequent damage. In addition to the many scientific and technical issues to be overcome prior to clinical application of these techniques, a number of ethical and legal issues must also be addressed to ensure a safe and realistic prospect for future fertility in these patients.