Mom with Rare Cancer Says Only 1 Person in the World Can Save Her Life

A single mom is opening up about her rare health diagnosis after discovering that there is just one matching donor with the stem cells that could save her life.

In September 2025, Sian Chathyoka became the only patient in the Welsh cities of Swansea and Cardiff to be diagnosed with a form of rare blood cancer, according to the charity Anthony Nolan. Having learned that a stem cell transplant from a “selfless stranger” would be needed in order for her to survive, she is now urging people across the globe to sign up as donors.

Chathyoka, 56, who has two children aged 18 and 13, had a very active lifestyle before being diagnosed with an aggressive form of myelofibrosis. She would swim in the sea in all weathers and managed the family’s seaside campsite.

“Since August, I’ve just been lying in bed because I’ve had no energy. I’ve had such a level of fatigue, I haven’t been able to do anything, and it’s been quite scary,” she told the charity.

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Myelofibrosis (MF) occurs when “a blood cell — a stem cell — transforms into a cancer cell,” according to the Cleveland Clinic. Healthy blood cells are crowded out by malignant copies, while substances are also released that damage bone marrow. 

Doctors are currently unsure what causes the process to begin and symptoms may not appear for years, according to the healthcare provider. Fatigue and heaviness in the upper left abdomen from an enlarged spleen are among the slowly worsening symptoms. 

Chathyoka became concerned when “extreme fatigue” left her unable to do her regular outdoor activities, per Anthony Nolan.

The former social worker was immediately sent for further medical tests after she told a doctor her weight unintentionally plummeted five pounds. 

“They came back and they were scattered all over the place,” she said of her test results.

After a CT and MRI scan revealed an enlarged spleen, Chathyoka was referred to the haematology department — which deals with blood and bone marrow conditions — where she was eventually diagnosed with myelofibrosis. 

“I couldn’t stop crying,” she said, per Anthony Nolan. “My condition is very rare and I’ve been told my disease is aggressive as well.”

“It’s very difficult to be upbeat and positive,” she said. “It’s absolutely petrifying. But you’ve got to forget about that and be positive.”

Chathyoka has been having weekly blood and platelet transfusions since her diagnosis, as well as treatment to shrink her enlarged spleen.

This month, she found out there is just one matching donor on the worldwide register available for her to undergo a stem cell transplant. 

“I’m lucky. I’m grateful that there is the possibility of a cure through a stem cell transplant,” said Chathyoka.

She continued, “What I have realized throughout this process is that nobody knows about stem cell transplants. A lot of my friends didn’t have a clue. That’s why I want to raise awareness by sharing my story.”

“Just signing up to the register, you can literally save a life. I feel really emotional because that’s as powerful as it is,” she concluded. 

Stem cells can be collected from bone marrow, peripheral stem cells and umbilical cord blood, according to the American Cancer Society. Donors are required to answer questions about their health, undergo a physical assessment and blood testing prior to donation.

Chathyoka has teamed up with the charity Anthony Nolan for the campaign “SignUpForSian” in the hopes that more people will join the potentially life-saving worldwide register.