Hormonal suppression for fertility preservation in the male

Introduction Radiation and chemotherapeutic regimens required for life-threatening diseases, such as cancer or exposure to environmental toxicants, may jeopardize the fertility of men of reproductive age causing permanent or temporary azoospermia. Young pre-pubertal patients who cannot supply a semen sample for cryopreservation of sperm have particularly poor fertility prognosis. In the USA alone about 17 000 men aged 15–45 years old are diagnosed each year with Hodgkin's disease, lymphoma, bone and soft tissue sarcomas, testicular cancer or leukemia. Of these, over 3000 are treated with doses of alkylating agents, platinum drugs or radiation that are sufficient to induce prolonged azoospermia. In addition, over 6000 boys under the age of 15 are diagnosed each year with cancer, including leukemia, nervous system tumors, lymphomas and other solid tumors. About 80% of them receive chemotherapy or gonadal radiation, and about 550 of the long-term survivors are azoospermic when they reach adulthood. Environmental and occupational toxicants can also produce prolonged azoospermia. This was most dramatically shown with dibromochloropropane (DBCP), as highly exposed manufacturing and agricultural workers had an increased incidence of azoospermia [1, 2]. In addition, sterility can be developed during development such as due to cryptorchidism or aging. Methods to prevent these effects on male fertility and to restore normal testicular function are of great importance. A variety of biochemical and biological approaches (thiol radioprotectors, prostaglandin analogues, growth factors, blockers of apoptotic pathways, and reduction in blood flow) have been tested to protect the testes in experimental animal model systems against radiation and chemotherapy (reviewed in [3]).