When 9-year-old Stephen Mondek learned his father needed stem cells to fight a returning cancer, his response was immediate: “When do we go?”
The young boy’s brave decision to donate six million stem cells has given his father, Nick Mondek, from Torrance, California, a second chance at life – and potnetially made him the world’s youngest stem cell donor.
Dad Nick’s life was turned upside down after acute myeloid leukemia returned “ferociously fast” following an initial remission.
His young son Stephen, who just turned 10 in August, underwent a six-hour blood cycling procedure at Cedars-Sinai Guerin Children’s Hospital to collect the life-saving stem cells.
But his selfless act saved his father – and transformed their relationship from father-son to father-hero.
Selflessly, Stephen said: “I wanted to make my dad’s cancer go away, and if I was sick, I would think he would do the same thing for me.”
Nick’s cancer journey began as far back as 2022 when he was first diagnosed with acute myeloid leukemia, a cancer affecting blood-forming cells in the bone marrow.
Initial treatment with stem cells from his older brother – a perfect genetic match – sent the disease into remission. But when the cancer returned aggressively, a search through the National Bone Marrow Registry failed to find a suitable donor.
Facing up to the stark reality, Nick remembered a friend whose 18-year-old son had donated stem cells to cure lymphoma. During an appointment last April, he asked the crucial question to his medical team.
“As my doctor came in the room, I said, ‘Could a 9-year-old who’s 70 pounds give us enough stem cells?'” Mondek told NBC Nightly News.
Dr. Ronald Paquette, clinical director of the Stem Cell and Bone Marrow Transplant Program at Cedars-Sinai Cancer, confirmed Stephen could be a viable donor. As a child inherits half their DNA from each parent, Stephen was naturally a half-match, which Paquette noted might actually make the transplant more effective.
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According to Cedars-Sinai staff, a half-matched immune system might more readily recognize and eliminate cancer cells in the bone marrow, while transplants from younger donors typically show greater success rates.
That news sparked the idea and with Stephen so keen to help his dad, the donation took off from there.
“The conversation with Stephen was pretty simple,” Mondek said. “I said, ‘Hey, Buddy, Dad’s sick and they need someone to give me stem cells, and they want to know if you want to get tested to see if you can do it.'”
After confirming Stephen’s suitability as a donor, medical staff carefully explained the procedure to make sure he could provide informed consent. And following the successful stem cell collection, Nick underwent chemotherapy to suppress his immune system before receiving the transplant.
An arduous six weeks of hospital recovery followed, but the timing worked out perfectly – Nick arrived home just in time to watch the final inning of Stephen’s little league game.
“He was very brave, and our team made sure everything went perfectly so that this young boy could help his father,” said Dr. Hoyoung Chung, a critical care pediatrician at Cedars-Sinai Guerin Children’s.
For Nick, who cherishes being a father above all else and loves playing catch with his son, the gift has transformed their relationship forever.
“He donated six million stem cells to save my life, so it’s not just an honor to call him my son, I’m proud to call him my hero,” Mondek said.
