Every starting line that Scott MacArthur has crossed this year has meant more than another race. Each has brought him closer to helping children and families facing life’s toughest diagnoses.
By the end of 2026, the St. Louis native plans to complete all eight Abbott World Marathon Majors and five Rock ‘n’ Roll Half Marathons while raising more than $100,000 for ALSAC, the fundraising and awareness organization for St. Jude Children’s Research Hospital. His 40th birthday inspired the challenge, though the reasons behind every mile were years in the making.
As a child, MacArthur dreaded the local 5K races that his family loved. While his father and two older sisters enjoyed running, MacArthur usually found himself near the back of the pack. “My dad would finish his race, turn around, and come back onto the course to find me,” MacArthur says. “He would run beside me, encourage me, and make sure I crossed the finish line.”
Those races became even more meaningful after his father died, following a nearly five-year battle with cancer.
Years later, another diagnosis changed MacArthur’s life again when a close family member was diagnosed with cancer. Today, that family member is in remission, though her experience reshaped the way that MacArthur thought about his own health, as well as how he wanted to honor his family’s journey.
“I needed to do something meaningful for myself to get my health back in check,” he says. “I also wanted to honor everything my family has been through and do something that makes a difference in the world.”
A birthday challenge with a bigger purpose
MacArthur completed his first marathon in 2018 with almost no training. He crossed the finish line exhausted and convinced that he would never run another one. Something shifted after he crossed the finish line, though. By the next morning, he wanted to do it again.
He entered lotteries for the world’s biggest races, hoping to earn a coveted spot. Most applications ended with rejection. One email for the London Marathon, however, included an unexpected caveat: If he couldn’t secure a place through the lottery, he could run for a charity.
The opportunity introduced him to fundraising through marathon running. After partnering with several cancer organizations, MacArthur discovered St. Jude while preparing for the 2025 Chicago Marathon. “I always thought St. Jude was the commercials you saw on TV,” he says. “Then I started learning about the mission and hearing the stories. I realized it was far more than what I thought.”
To celebrate turning 40, MacArthur approached the St. Jude team with an ambitious proposal: He wanted to run all eight Abbott World Marathon Majors in a single calendar year while raising money for children and families facing catastrophic illnesses.
The Abbott World Marathon Majors is a global series featuring eight of the world’s most prestigious marathons, held in Tokyo, Boston, London, Sydney, Berlin, Chicago, New York, and Cape Town. Although many runners spend decades trying to complete the series, MacArthur aims to take on all eight in a single year, often paying for his own travel, running the race, and returning home almost immediately before preparing for the next challenge.
“They were like, ‘You want to do what?’” he recalls with a laugh. But the answer quickly became yes.
So far, he has completed four World Marathon Majors this year, along with multiple half marathons. By December, he plans to cross the final finish line at the St. Jude Memphis Marathon, after completing 18 marathons overall.
What began as a way to mark a milestone birthday has become a tribute to his family and a source of hope for countless others.
“I’ve gotten so much more out of this experience than just doing something cool for turning 40,” MacArthur says. “It’s been completely eye-opening.”
Research that reaches children around the world
MacArthur’s journey also opened his eyes to a side of St. Jude that many people never fully understand.
While the hospital is located in Memphis, its discoveries reach children beyond Tennessee. Researchers at St. Jude shares their findings with hospitals around the world, helping improve treatments for childhood cancer, sickle cell disease, and other life-threatening illnesses. Children receiving care in St. Louis may be benefiting from treatment protocols developed by St. Jude researchers.
“I think a lot of people hear St. Jude and immediately think Memphis,” says Christy Fath, Area Managing Director of ALSAC. “What many don’t realize is that our research is shared worldwide. It would not be unusual for a child receiving treatment here in St. Louis to be following a protocol developed by researchers at St. Jude.”
Research has helped dramatically improve childhood cancer survival rates during the past several decades. Equally important, St. Jude families never receive a bill for treatment, travel, housing, or food, allowing parents to focus on helping their children heal instead of worrying about financial strain.
“When a family receives a diagnosis, their world changes in an instant,” Fath says. “Removing those financial burdens allows them to focus on what matters most, helping their child get well.”
MacArthur says learning more about the mission strengthened his commitment with every race.
“When you’re going through cancer, you need to focus on the patient and the family,” he says. “I wish someone could have helped my family the way St. Jude helps so many others. That’s what inspires me every time I step onto a starting line.”
One story can inspire another
MacArthur has already raised more than $90,000 for St. Jude this year, with support arriving from friends, coworkers, former classmates, and even people he hasn’t spoken with in decades. Some donors have shared their own cancer stories. Others have revealed that they were once St. Jude patients themselves. Every conversation reminds him that his journey reaches much further than the miles on his training schedule.
“I wanted to have an impact on my community and on people I may never meet,” MacArthur says. “If sharing my story helps someone support St. Jude or inspires someone to take on their own challenge, then every mile has been worth it.”
Fath hopes that readers see the same opportunity. “I hope that people are inspired by MacArthur’s story to do something bigger than they think they can,” she says. “There are so many ways to support St. Jude, through volunteering, fundraising, community events, or simply helping spread awareness. Every person has the ability to make a difference.”
MacArthur’s final race of the year will take him through the St. Jude campus in Memphis, where patients and families line portions of the course to cheer on runners toward the finish line. He already knows that it will be the most emotional race of his life.
Years ago, his father ran back through a crowded 5K course to encourage a young boy who thought he couldn’t finish. Today, every marathon honors those memories while helping give more children and families hope for the future
“It’s been far more meaningful than I ever imagined,” MacArthur says. “I’m not doing this for recognition. I’m doing it because if even one more family has a little more hope, every mile has been worth running.”
This post was created by SLM Partner Studio on behalf of St. Jude. To support St. Jude or Scott MacArthur, scan the QR code to the right or visit stjude.org/midamerica to donate and learn more.
