Understanding survival rates for donor stem cell transplants

50% survival

You may have heard the statistic that 50% of patients survive for five years or more after a stem cell transplant from a donor.

This may be a difficult statistic to hear – but it doesn’t tell the full story. This number is an average, so many people have a better chance of survival and even a cure after their transplant. A patient’s risk depends on many factors including the type of disease they have, their age, or if they have other health conditions.

If you’re due to have a stem cell transplant, your medical team will be happy to talk to you about its likelihood of success relevant to your specific treatment. Rest assured, they would not suggest a stem cell transplant if they were not confident that it was suitable for you.

Nevertheless, the statistics highlight that there is more work to do. We won’t stop our work until every patient who needs a stem cell transplant can survive and thrive. The whole story behind the 50% statistic reveals how far stem cell transplants have come, and how much further we have to go.

The reality in numbers

The 50% statistic is based on an average for adult patients with blood cancers who are receiving a transplant from a donor (allogeneic).

Note: it’s important to emphasise that this article focuses on allogeneic stem cell transplants. Autologous transplants (using a patient’s own cells) generally have higher survival rates.

The most recent data from the BSBMTCT (British Society for Blood and Marrow Transplantation and Cellular Therapies) shows that for adult patients receiving a donor transplant between 2019-2023 for blood cancers, the five-year survival rate was 57%. For children in the same group, the five year survival rate was 77%.

For non-malignant conditions, such as immune deficiencies, five-year survival rates were 84% for adults and 91% for children. Between 2019-2023, stem cell transplants for non-malignant conditions only make up around 10% of transplants from donors in adults, but around 50% in children.

Digging further into the numbers

The reality is that for stem cell transplants, an individual patient’s chance of survival after their transplant will depend on a number of things.

Survival rates look very different between adult and paediatric patients. The main reason for this is that older patients will typically have other health issues that can make treatment more challenging – and often have higher risk diseases. Children are also known to be a bit more resilient in handling the stresses of a transplant.

Similarly, someone’s general health can affect the chance of a successful transplant. That’s why support before and after a transplant involves keeping patients as fit and healthy as possible.

People with more advanced disease, or who aren’t in remission before their transplant, may have a lower chance of a successful outcome. Some diseases are more likely to relapse after a transplant. Depending on the type of treatment a patient has, some transplants might come with a higher risk of complications like graft versus host disease (GvHD).

Each patient’s treatment will look different, and some patients may require stronger conditioning treatments before their transplant that could affect the risks involved in their treatment.

We also know that in the UK, Black and Asian patients have an increased risk of serious complications compared to white patients. We are working to better understand this issue as one of our key priorities, and are applying several strategies to identify and address the causes of inequities in stem cell transplants.

Why survival rates are not as good as we'd like them to be

Survival rates have improved over time – in the earliest days of stem cell transplants, the chance of success was close to zero. The first 200 patients to receive stem cell transplants, between 1957-1967, all passed away soon after their transplant.

Now, stem cell transplants provide a lifeline to patients who may not have had any other options just a few decades ago. But we know there’s a long way to go before every single patient can survive and thrive.

The reason why survival rates are still below where we’d want them to be is because a stem cell transplant is still a major procedure that puts the body under a lot of stress. Replacing someone’s immune system comes with significant risks that scientists are still figuring out how to manage – not to mention the strain that conditioning treatments can put on the body in order to carry out the transplant in the first place. Doctors must constantly balance the risk of serious side effects with the risk of a patient’s disease returning, especially if the disease is aggressive.

As our understanding of stem cell transplants has improved, more patients than ever before have become eligible for transplants. This includes patients with more advanced disease, or older patients, who may have worse survival rates. At the same time, patients who might have previously had a transplant with a good chance of survival may now opt for newly discovered treatments instead, which also affects survival data. These two factors mean that overall survival rates may not appear to be significantly increasing, even though we’re constantly improving the way transplants are done.

How we can improve survival

A key part of our work at Anthony Nolan is undertaking our own research into stem cell transplants, helping us improve survival for all patients. We are part of a global community of scientists and clinicians who are making huge strides in our understanding of stem cell transplants, bringing major improvements for patients.

Since the inception of our research institute in 1996, we’ve made several discoveries that have influenced the way transplants are performed around the world. From confirming younger donors improve survival rates in the UK, to identifying key genetic factors in donor matching now used globally, the work of our researchers has consistently applied our scientific knowledge to directly improve the success of transplants. 

We’re also researching new cell therapies that could help boost the success of stem cell transplants, or even provide an alternative treatment in some cases.

While research is a crucial part of our work to improve survival, we are also determined to improve the awareness of stem cell transplants and campaign for better support for patients during and after their transplants. More awareness and better healthcare policies are key parts of enhancing stem cell transplants for patients.