Rare cancer: Woman finds only one matching stem cell donor worldwide

In a remarkable and sobering case, a 56-year-old woman from Swansea, Wales, is facing a life-threatening situation where her survival hinges on a single, identified potential donor. Sian Chathyoka was diagnosed with an aggressive form of myelofibrosis last year and requires a stem cell transplant, but currently, only one matching donor has been found on the global registry.

A Rare Diagnosis and Limited Options

Sian, a former social worker and mother of two, described the difficulty in remaining optimistic after receiving her diagnosis. Prior to becoming ill, she led an active life, enjoying activities like year-round sea swimming, running her family’s campsite, and caring for her children, aged 18 and 13. She first noticed something was wrong when experiencing “extreme fatigue” and unexplained weight loss.

The Urgency of Stem Cell Donation

Stem cell transplants are often described as a “last chance of life” for individuals battling blood cancers, according to the charity Anthony Nolan. Sian is now preparing for the transplant from this “selfless stranger” and is using her experience to advocate for increased stem cell donor registration.

Did You Know? The Anthony Nolan and NHS Stem Cell Registry currently has over 2.3 million registered potential stem cell donors.

Understanding Myelofibrosis and Treatment

Sian’s diagnosis of myelofibrosis, a rare form of blood cancer, was confirmed in September 2025 after initial blood tests revealed abnormalities. Further scans revealed an enlarged spleen. She has since been undergoing treatment to reduce the size of her spleen and receiving regular blood and platelet transfusions.

The Importance of Donor Registries

Sian expressed surprise at the lack of public awareness regarding stem cell donation. She emphasized the potential to save lives by simply signing up for the registry, stating, “Just signing up to the register, you can literally save a life.” The NHS estimates that 30,000 new potential stem cell donors are needed in the UK each year to meet the growing demand.

Expert Insight: The case of Sian Chathyoka underscores the critical importance of a diverse and robust stem cell donor registry. The limited number of matching donors highlights the challenges faced by patients with rare blood cancers and the need for continued recruitment efforts to expand the pool of potential lifesavers.

What Happens Next?

If the transplant proceeds as planned, Sian will undergo a process to receive stem cells from her matched donor. The method of collection – whether through blood donation or bone marrow extraction – will depend on the donor and medical protocols. Following the transplant, Sian will require ongoing monitoring and care to manage potential complications and assess the success of the procedure. It is possible that, even with a successful transplant, Sian will face a long recovery period. Should the transplant not be successful, alternative treatment options may be explored, but her prognosis remains uncertain.

Frequently Asked Questions

What is myelofibrosis?

Myelofibrosis is a rare form of blood cancer where the bone marrow is damaged and doesn’t make enough healthy blood cells, according to information provided in the source.

How are stem cells donated?

Most stem cells are donated through a blood donation process at a specialist center, but in approximately 10% of cases, they are extracted from the bone marrow during a hospital procedure.

How many people are on the stem cell register?

The Anthony Nolan and NHS Stem Cell Registry has more than 2.3 million registered potential stem cell donors.

Considering the critical need for donors, what steps, if any, would you take to learn more about becoming a stem cell donor?