The initial testicular tissue transplant aimed to demonstrate safety and feasibility, according to Orwig. Ultrasound examinations revealed that the recipient, Hsu, experienced no harm to his testicular tissue, and his hormone levels remained normal. However, his semen still lacks sperm at this stage.
Orwig’s team, which has been banking testicular tissue from children since 2011, is preparing for additional transplants as some of these patients reach reproductive age. The group has been granted permission by an institutional review board to perform both stem cell and testicular tissue transplants as part of a clinical trial.
Researchers are also exploring an alternative method of transplanting immature testicular tissue. This involves inserting a preserved tissue piece under the scrotum’s skin, with the hope that it will mature and produce sperm eventually. In previous experiments with monkeys, Orwig and his team transplants testicular tissue and later extracts sperm from it to fertilize eggs for embryo transfer into surrogate female macaques, resulting in live births.
Sperm retrieval from the grafted tissue involves cutting away a sliver of skin, a less invasive procedure compared to stem cell transplants, which require opening the testis.
Initially, when Orwig’s team began collecting testicular tissue, they believed isolating stem cells from the tissue before freezing would yield better results. This was the approach taken with Hsu. However, they later found that cryopreserving whole tissue pieces could potentially result in an equal or greater number of stem cells. This discovery means Hsu can only undergo a stem cell transplant, while other patients with preserved whole tissue pieces have the option to opt for either transplant type.
In January, researchers from Vrije Universiteit Brussel and Brussels IVF in Belgium announced their performance of the first testicular tissue transplant on a patient who experienced chemotherapy in childhood. Monitoring will occur over one year to test semen for sperm presence. After a year, some transplanted tissue will be removed to check for sperm.
Robert Brannigan, president-elect of the American Society for Reproductive Medicine and a professor of urology at Northwestern University, highlights that cancer treatments, while life-saving, often result in permanently impaired fertility. He emphasizes the need for further study of both approaches—stem cell and testicular tissue transplantation—as viable options for preserving fertility.
A similar procedure called ovarian tissue transplantation is available for female cancer patients, resulting in over 200 live births globally. While men undergoing chemotherapy can often freeze sperm, women may not have the same opportunity for egg freezing due to time constraints before treatment. In such cases, ovarian tissue can be preserved for future use.
Jonathan Routh, a pediatric urologist at Duke Health, appreciates advancements in fertility preservation for young men, similar to those available for women. While the primary goal is to save lives, enhancing the quality of life afterward remains essential, and this study holds promise for future impact.
Hsu acknowledges the experimental nature of the technology and recognizes that it may not benefit him personally. Nevertheless, he hopes these techniques will eventually provide more reproductive options for other childhood cancer patients. He emphasizes the need for continued research and data collection to improve outcomes for individuals like himself in the future.
