We've gone through life together and I don't want our story to end here.
In Cardiff, a 24-year-old woman named Caitlin Leggett stands at the edge of what medicine can offer her, having exhausted the treatments available in the UK for a leukaemia that keeps returning. The story carries a particular ache: her identical twin sister, discovered to share her DNA only through the process of diagnosis, cannot donate the cells that might have saved her — a biological closeness that became, paradoxically, a closed door. Now Caitlin and Grace are raising £500,000 to pursue experimental therapies abroad, in a search that is as much about refusing an ending as it is about finding a cure.
- Caitlin's leukaemia has returned after chemotherapy, a stem cell transplant, a clinical trial, and radiotherapy — UK doctors now offer only palliative care and a six-month prognosis.
- The discovery that the twins are genetically identical, made only during Caitlin's diagnosis, rendered Grace ineligible as a donor — the perfect biological match locked out by the very fact of her perfection.
- With no curative options remaining in the UK, the sisters are pursuing specialised leukaemia programmes in the US and CAR-T cell immunotherapy available in China or Singapore.
- The barrier is financial as much as medical: £500,000 must be raised by a family confronting both a terminal timeline and the logistical weight of treatment on the other side of the world.
- At the centre of the fight is something simpler than medicine — two 24-year-old twins who have shared everything, and are not ready to stop.
Caitlin Leggett was 24 when a rash that wouldn't fade led to blood tests, and within a day she was in the Teenage Cancer Trust unit at University Hospital of Wales, learning she had acute myeloid leukaemia. Chemotherapy brought remission, and a stem cell transplant from an unrelated donor seemed to hold. But in May 2026, a test Caitlin herself requested revealed the cancer had returned. She was given six months to live.
The cruelty of her situation had a particular twist. Caitlin's twin sister Grace had been tested as a potential donor during the initial diagnosis — and that testing revealed something neither sister had known: they were genetically identical, not fraternal as they had always believed. The discovery that should have been a gift became an obstacle. Their near-identical DNA made Grace ineligible to donate. The one person whose cells might have been a perfect match was ruled out by the very closeness that defined them.
Caitlin had planned to join the Army as an intelligence officer after graduating in 2024. That future gave way to a year of treatments — each one retreating the cancer only for it to return. Now, with UK medicine offering nothing further that could cure her, the sisters are looking abroad: specialised leukaemia programmes in the US, or CAR-T cell therapy available in China or Singapore. The cost is £500,000, and they have begun fundraising.
"We're only 24," Grace said. "Being twins, you're not supposed to have one twin not be there." Caitlin put it plainly: "We've gone through life together and I don't want our story to end here." What comes next depends on whether the money arrives, whether the treatment works, and whether the timeline her doctors have given her can be pushed far enough to find out.
Caitlin Leggett was 24 years old when she noticed a rash that wouldn't fade. It was March 2025. She tried the creams from the pharmacy. Nothing worked. Blood tests followed, and within a day she was sitting in the Teenage Cancer Trust unit at University Hospital of Wales in Cardiff, learning that she had acute myeloid leukaemia—an aggressive cancer of the white blood cells that had announced itself with almost no other warning.
Two months of chemotherapy brought remission. Then came a stem cell transplant, the kind of procedure that destroys the diseased marrow and replaces it with healthy cells from a donor. For a moment, it seemed to have worked. But in May 2025, just as the monitoring schedule was about to stretch out to quarterly checkups, Caitlin pushed back. She asked her consultant for one more test in the interim. That test found the cancer had returned. It was now May 2026. She was told she had six months to live.
The cruelty of her situation deepened when she learned what her own biology had done to her chances. Caitlin has an identical twin sister, Grace. They had grown up believing they were fraternal twins—they developed in separate amniotic sacs, which typically means non-identical. But when doctors tested Grace as a potential stem cell donor during Caitlin's initial diagnosis, they discovered something unexpected: the twins' genetic markers were exactly the same. They were identical after all. The discovery should have been a gift. Instead, it meant Grace could not donate. Their near-identical DNA made her ineligible. The one person whose cells might have been a perfect match was locked out by the very thing that made them perfect.
Caitlin had been planning to join the Army after graduating in July 2024. She was going to train as an intelligence officer. That future dissolved in the months that followed her diagnosis. Instead, she has spent the past year cycling through treatments—chemotherapy, a stem cell transplant from an unrelated donor, a clinical trial with menin inhibitors, extra radiotherapy, another round of monitoring. Each time the cancer retreated, it came back. Each time it came back, the options narrowed.
Now, with UK doctors saying there is nothing more they can offer that would cure her, Caitlin and Grace have turned to overseas treatment. The options are specialized leukaemia programs in America, or CAR-T cell therapy—a form of immunotherapy—available in China or Singapore. The cost is £500,000. The sisters have set up a fundraising page. They are asking for help to buy time, to buy a chance, to buy the possibility that Caitlin might not have to leave Grace behind.
"We're only 24," Grace said. "Nobody expects this to happen. Being twins as well, you're not supposed to have one twin not be there." Caitlin's response was simpler: "It's unthinkable. We've gone through life together and I don't want our story to end here." They had lived together at university. They had discovered they were identical only because of her illness. Now they are fighting to stay together, to keep the story going, to refuse the ending that the cancer is trying to write for them. What comes next depends on whether the money can be raised, whether the overseas treatment works, and whether the six-month timeline her doctors have given her can be stretched into something longer—long enough to see what happens next.
Citações Notáveis
Being twins as well, you're not supposed to have one twin not be there.— Grace, Caitlin's identical twin sister
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.— Caitlin Leggett
A Conversa do Hearth Outra perspectiva sobre a história
Why did discovering they were identical twins actually make things worse for Caitlin's treatment?
Because identical twins share the same genetic markers. When Grace was tested as a potential stem cell donor, the doctors found their DNA was essentially identical. That should have been perfect—except it meant Grace couldn't donate. The transplant protocols won't allow it when the donor and recipient are genetically that close. It's a paradox. The thing that made them most alike is what kept them apart when Caitlin needed her most.
So the rash was the only symptom she had?
Yes. That's what's striking about her case. Acute myeloid leukaemia usually announces itself with fatigue, bruising, bleeding, weight loss. Caitlin had none of that. Just a rash that wouldn't clear. If she hadn't been persistent about getting it checked, if the pharmacy cream had worked, she might not have gone to the hospital at all.
She had remission twice. Why did it come back both times?
That's the question no one can answer yet. The first time, after chemotherapy and the stem cell transplant, it returned to her skin in August. The second time, after a clinical trial and more radiotherapy, it came back again just before the transplant was scheduled. The cancer kept finding its way back. That's why UK doctors are now saying they can't cure it—only manage it for a few more months.
What makes the overseas treatments different?
They're experimental. The US programs offer specialized leukaemia protocols that aren't available in the UK. CAR-T therapy in China or Singapore is a form of immunotherapy that essentially reprograms immune cells to attack the cancer. These aren't standard treatments. They're cutting-edge, expensive, and unproven for her specific situation. But they're also her only shot at a cure rather than just survival.
How much time does she actually have?
Six months, according to her doctors. That's the estimate if she stays in the UK and continues palliative care. The overseas treatment is a gamble that she can extend that, or beat it entirely. But it requires raising half a million pounds in that window, arranging travel, getting accepted into a program, and starting treatment. The clock is running.