Oncofertility: technical challenges in immature testicular tissue banking

Abstract

The gonadotoxicity of cancer therapy ranges from severe to mild effects on spermatogenesis, structural, functional, and genetic integrity of spermatozoa. However, these effects are even more pronounced in prepubertal males due to the susceptibility of the prepubertal testis to cytotoxic therapy. The proliferating germ cells in the prepubertal testis are mitotic in nature, thereby becoming a target for anticancer agents. Immature testicular tissue (ITT) cryopreservation is offered as the only fertility preservation (FP) strategy for prepubertal males facing gonadotoxic risk, though it is still experimental in nature. Multiple cryopreservation protocols have been developed to ensure safe and efficacious storage of the tissue and to enable maximum recovery of germ cells during thawing. The thawed tissue can then be used for fertility restoration by either in vitro spermatogenesis or transplantation to reinitiate spermatogenesis and thereby result in the production of mature spermatozoa. However, there are many challenges to overcome to successfully offer this procedure as an established one. This mini-review gives an overview of the progress in ITT cryopreservation and fertility restoration procedures, along with the other challenges.