9-Year-Old Donates Stem Cells To Save His Father’s Life

Photo of Nick Mondek with his family after the stem cell procedure is from Cedars-Sinai.

Stephen Mondek, only 9 years old, from Torrance, became the world’s youngest stem cell donor to save his father Nick Mondek when his acute myeloid leukemia returned.

Mr. Mondek’s Battle with Cancer

Back in 2022, anesthesiologist Nick Mondek was diagnosed with acute myeloid leukemia. He needed rapid treatment, an injection of donor stem cells.

His First Transplant and Remission

His older brother was a perfect genetic match and was willing to donate to help his brother.

After the donation of stem cells, Mr. Mondek went into remission. Unfortunately, his cancer came back “ferociously fast.” The only option was to find another stem cell donor.

Here is a brief explanation of how a stem cell injection works: “This form of leukemia affects the blood-forming cells in the bone marrow, but an injection of stem cells can form the basis of a new immune arsenal that can locate and attack the leukemia tumors.”

Searching for a Donor

A search was conducted through the National Bone Marrow Registry, but there was not a match to be found. When all hope was lost, Mr. Mondek recalled a very specific case.

His friend with lymphoma had received a lifesaving stem cell donation from his 18-year-old son. He figured it could not hurt to try, and asked his doctor, “As my doctor came in the room, I said, ‘Could a 9-year-old who’s 70 pounds give us enough stem cells?’”

Enter Stephen Mondek. The young boy said to NBC Nightly News that he did not hesitate to agree, saying, “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.”

Making It Happen

Ronald Paquette, the clinical director of the Stem Cell and Bone Marrow Transplant Program at Cedars-Sinai Cancer, confirmed that Stephen Mondek was a possible donor.

Why Stephen Was a Match

This is because a child receives half of their DNA from each parent, making Stephen what is called a half-match. Paquette said that “a half-match might make the transplant more effective.”

A half-matched immune system might more easily recognize and kill the cancer cells in Mondek’s bone marrow. Moreover, transplants from younger donors tend to be most successful.

Mr. Mondek said, “The conversation with Stephen was pretty simple. 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.’” Stephen’s response was simple: “When do we go?”

Preparing for Donation

The next course of action was testing to ensure that Stephen was a compatible donor. When the test gave the all clear, the care team at Cedars-Sinai Guerin Children’s made sure that he understood the procedure.

Several weeks of pre-donation preparations later, Stephen was admitted to the pediatric intensive care unit for the donation. He was placed under general anesthesia for doctors to insert a catheter into a vein in his neck.

Stephen’s blood cycled through a centrifuge that separated out the stem cells, which took six hours. Nick Mondek said, “Being an anesthesiologist, I put people to sleep every day, so I reassured myself that everyone wakes up when they go to sleep under anesthesia. But during the whole process that I’ve gone through, those 60 minutes when Stephen was asleep were probably the toughest.”

How It Went

Everything went according to plan and Stephen’s stem cells were collected and frozen. Then the following week, Nick Mondek spent six days at Cedars-Sinai receiving chemotherapy which would suppress his immune system to make sure his body would not reject the donor cells.

Transplant Day and Recovery

After that, transplant day had arrived. Paquette said, “Transplant day is always dramatic. The patient knows that they cannot survive without the stem cells, and the delivery of the stem cells into their body is like a rebirth. We call that day their stem cell birthday.”

Paquette also explained that “it takes two to three weeks for the newly transplanted stem cells to begin to grow.” This meant a two-week stay in the hospital for Mr. Mondek to protect his immune system.

Paquette also said that “it could take a year or more to determine whether the new immune system Mondek received from Stephen can beat his leukemia.” Everyone is optimistic. Mondek has said since the stem cell donation, “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.”

To learn more about how stem cell transplants work to treat cancers like leukemia, see Stem Cell or Bone Marrow Transplant from the American Cancer Society.

The Decision To Donate

For Stephen Mondek, the decision to donate stem cells to save his father’s life was easy.

A Young Hero and New Hope

Critical care pediatrician at the children’s hospital Hoyoung Chung, DO, said, “Stephen was very brave, and our team made sure everything went perfectly so that this young boy could help his father.” Cancer is unpredictable; just when you think you’ve beat it, there’s always the chance that it could come back.

That was the case for Nick Mondek, but now there is new hope. He is a fighter with a loving family worth sticking around for. We are all hoping that he pulls through and comes back stronger than ever.

For another reflection on rest and resilience during hard seasons, read Why I Stopped Earning My Rest.