A groundbreaking experimental procedure at the University of Pittsburgh Medical Center (UPMC) has resulted in the first known transplant of sperm-producing stem cells in a childhood cancer survivor, potentially opening new avenues for fertility preservation in pediatric oncology patients.
Jaiwen Hsu, now 26, was diagnosed with bone cancer at age 11. While doctors believed chemotherapy could save his life, they warned it would likely compromise his fertility. His parents enrolled him in an innovative research program at UPMC that preserved testicular cells from young boys with cancer, hoping to safeguard their future reproductive options.
"The science behind it is so incredibly new that right now it's kind of a waiting game," said Hsu, who lives in Vienna, Virginia. "It's kind of eagerly crossing our fingers and hoping for the best."
The Fertility Challenge in Pediatric Oncology
While 85% of children with cancer now survive into adulthood, approximately one in three experience infertility as a consequence of chemotherapy or radiation treatments. Adult cancer patients can preserve fertility by banking sperm, eggs, or embryos before treatment begins. However, children diagnosed before puberty lack this option since they don't yet produce mature reproductive cells.
This gap in fertility preservation options represents a significant unmet need in pediatric oncology. Boys are born with stem cells in the testes that only begin producing sperm after testosterone levels rise during puberty. These cells are particularly vulnerable to cancer treatments.
The Experimental Procedure
Dr. Kyle Orwig, a reproductive scientist at UPMC, has pioneered research on preserving and utilizing testicular cells to restore fertility, with funding from the National Institutes of Health. The procedure begins with a biopsy-like extraction of a small amount of testicular tissue containing millions of cells, including the critical sperm-producing stem cells.
Since 2011, Orwig's team has cryopreserved samples from approximately 1,000 prepubertal boys. While it's impossible to determine if each sample contains sufficient viable stem cells, the research has shown promise in animal models. In 2019, Orwig successfully used preserved testicular tissue from a young male monkey to facilitate the birth of a healthy baby monkey through an animal version of IVF.
In November 2023, Hsu became the first participant to return as an adult for reimplantation of his preserved cells. The procedure involved thawing his stored cells and injecting them under ultrasound guidance.
"We're not expecting a miracle result," Orwig cautioned in a paper posted online this week. The research has not yet undergone peer review.
Current Status and Future Implications
Orwig noted it's premature to determine if the experiment succeeded, and standard fertility tests may not detect small amounts of sperm production. Animal testing suggests assisted reproductive technologies would likely be necessary to detect and retrieve any sperm resulting from the procedure.
The field is advancing globally. Belgian researchers announced a similar experiment in January, though their approach involved implanting pieces of testicular tissue rather than isolated cells in a childhood cancer survivor.
"These developments are of great importance," said researcher Ellen Goossens of Vrije Universiteit Brussel. While animal research "was very promising, transplantations in humans will be the only way" to determine clinical efficacy.
Broader Applications in Oncofertility
Similar research using immature ovarian tissue is underway for female childhood cancer survivors, according to Dr. Mahmoud Salama, director of the Oncofertility Consortium at Michigan State University. These parallel approaches highlight the growing importance of fertility preservation across genders in pediatric oncology.
Hsu acknowledges his experimental transplant may not succeed but emphasizes its value in advancing the field. "I'm grateful my parents years ago made a call that gave me the option to make the choice for myself today," he said.
The research represents a significant step forward in addressing the long-term quality of life concerns for childhood cancer survivors. As survival rates continue to improve, preserving fertility options becomes increasingly important for ensuring these patients can lead full lives after cancer treatment.
