Caitlin Leggett is raising money for overseas treatment
08:18, 09 Jun 2026Updated 12:34, 09 Jun 2026
Caitlin said the idea of leaving her identical sister alone was ‘unthinkable’(Image: PA Real Life)
A 24-year-old twin given six months to live after her leukaemia returned is raising £500,000 for potentially curative treatment overseas, saying the thought of leaving her identical sister alone is “unthinkable”. Caitlin Leggett, who lives in Cardiff, was diagnosed with acute myeloid leukaemia – an aggressive cancer of the white blood cells – in April 2025, with a persistent rash being the only sign that something was wrong.
After months of chemotherapy and a stem cell transplant in December 2025, Caitlin achieved complete remission. But in May 2026, she said doctors found the cancer had returned and the treatment options available to her in the UK were unlikely to be curative.
Having been given just six months to live on her current treatment plan, she has decided to pursue potentially curative treatment abroad – most likely in the US – where treatment and associated costs could reach £500,000. Caitlin’s twin sister Grace Leggett, who has quit her job as a complex care personal assistant in Bristol to move back to Cardiff to be closer to her family, said watching Caitlin go through all of this while facing the prospect that she might lose her sister in six months was incredibly painful.
“We’re only 24 – nobody expects this to happen… Being twins as well, you’re not supposed to have one twin not be there,” Grace told PA Real Life. “It’s unthinkable,” Caitlin added. “We’ve gone through life together and I don’t want our story to end here.”
Caitlin’s stem cell transplant was delayed due to difficulties finding a donor(Image: PA Real Life)
Caitlin and Grace have always been very close – even sharing a student house together at the University of Bristol. After graduating in July 2024, Caitlin had planned to join the Army, wanting to train as an intelligence officer.
She had her requisite medical assessment booked for April 2025, but in March of that year she said she developed a rash that did not go away despite using generic creams from the pharmacy. A few weeks later, she said she went to her GP, who thought she may have a virus and ordered some blood tests to investigate, which were taken on April 3 2025.
She said she was instructed to report to the Llewellyn Teenage Cancer Trust unit at University Hospital of Wales in Cardiff the following day, and immediately realised it was not good news. At the appointment on April 4, 2025, she was diagnosed with acute myeloid leukaemia (AML) – an aggressive cancer of the white blood cells.
According to the NHS, symptoms of AML can include looking pale, feeling tired or weak, breathlessness, unusual and frequent bruising or bleeding, and losing weight without trying to, but Caitlin said she experienced none of these – just the unusual rash, which can also be a sign of blood cancer. After learning that treatment would involve a stem cell transplant, replacing the destroyed cancerous cells with healthy stem cells from a donor, the twins’ whole family was tested to see if any of them could be a match.
According to the blood cancer and blood disorder charity DKMS, more than 2,000 people each year in the UK need a blood stem cell transplant, but just 7% of the entire eligible population in the UK are registered as potential donors. Both Caitlin and her sister Grace had registered as stem cell donors “years and years ago” and initially Grace was told that she would likely be a match for her sister.
Caitlin has been told that she has six months to live(Image: PA Real Life)
Their entire lives, they had believed that they were fraternal twins, meaning there was a high chance that her stem cells would be accepted by Caitlin’s body and would aid her recovery. But, genetic testing in June 2025 revealed they were actually monozygotic twins, meaning they were identical.
“I always wished I was an identical twin – I liked being a twin, but being an identical twin is a bit cooler,” Grace said. “It’s really weird to think that I’m basically Caitlin!”
This discovery meant a setback for Caitlin’s treatment – as they have near-identical DNA, Caitlin said “the whole concept of the transplant wouldn’t work” as the body has to recognise the stem cells as foreign in order for them to combat the cancerous cells. Unfortunately, no other family members were a match, either.
While waiting to find an alternative donor from the register, Caitlin achieved remission in May 2025 after two months of chemotherapy. But in August 2025, she was told that the cancer had returned to her skin – an abnormal relapse which, she said, was exacerbated by difficulties finding a suitable stem cell donor.
Caitlin then took part in a menin inhibitors clinical trial in Manchester to eliminate the leukaemia in her skin, which was successful and put her into complete remission – exactly what her consultants wanted before her stem cell transplant, as it gives a better chance of it working. She was given another transplant date in December 2025 with another donor.
But a week before this second transplant date, the cancer returned to her skin. She was still able to have the transplant, which took place in December 2025, but needed extra full-body radiotherapy beforehand. The treatment was deemed to be successful and she was told she was in remission again in January 2026.
Caitlin was then scheduled for monthly bone marrow monitoring for three months, to check that the cancer had not returned, which were set to decrease to quarterly tests from March 2026, “but I wasn’t too happy about that”, she explained.
“I didn’t feel like it was safe to just go straight to three, so I persuaded my consultant to give me an extra one in May,” she said. “On that extra one, they found that the leukaemia had come back. Initially, the blast count came back at 5.7%, just over remission, but then about a week later it went up to 37%. So it’s quite fast-growing.”
Caitlin Leggett was diagnosed with acute myeloid leukaemia in April 2025(Image: PA Real Life)
From May 2026, Caitlin has taken part in another drug trial for Bleximenib and is waiting to see whether her body responds. Her doctors say there is another drug trial option in case it is not successful – but she has been advised that these treatments are not curative. She said she has been told that a second stem cell transplant cannot be performed in the UK, and doctors have predicted that her current treatment plan will help her survive for just six more months.
So, she has decided to pursue curative treatment abroad – she is considering specialised leukaemia treatment in America or CAR-T cell therapy, a type of immunotherapy, in China or Singapore, both of which will cost hundreds of thousands of pounds. Caitlin and Grace have set up a GoFundMe page titled Saving Caitlin to try and fundraise £500,000 to cover the cost of the expensive overseas treatment as well as transport, accommodation and sustenance for accompanying family members, and are “appealing to anyone and everyone to help us in this fight”.
If the twins are unable to raise the money needed, it is unlikely that Caitlin will live to see her 25th birthday. “It’s incredibly difficult to think about,” Caitlin said.
“At 24, I always assumed I had my whole life ahead of me. There are so many things I still want to do, places I want to see, and memories I want to make with the people I love.
“What I would miss most isn’t one particular event, it’s the chance to keep living an ordinary life with the people I love and growing older alongside my twin sister. Those are the things that matter most to me, and that’s why I’m doing everything I can to find another treatment option. I don’t want to miss out on the future we always thought we’d share together.”
You can donate to Caitlin’s fundraiser on her page.