In this blog, our Science Communications Manager, Jonathan Kay, looks at a recent study that highlights the potential benefits of selecting a cord blood transplant over a matched related donor for some patients with blood cancer.
Introduction
When someone needs a stem cell transplant to treat their blood cancer or blood disorder, they can rely on organisations like Anthony Nolan to find them a suitable donor. This could be a family member, a willing volunteer on the stem cell register, or an umbilical cord blood donation collected soon after a baby’s birth. Anthony Nolan collects cord blood cells at five hospitals around the UK, and our cord blood bank contains approximately 10,000 frozen samples ready to treat patients as soon as they are needed.
We know cord transplants have some advantages over other types. Cord stem cells are not as mature as adult stem cells, which means it’s easier to find a suitable match and they are less likely to cause graft versus host disease (GvHD) long term. They are also rapidly and easily available because they are frozen and stored until needed.
Despite this, cord transplants and haploidentical transplants that use a half-matched close relative, are often only used as an alternative when a suitable related or closely matched un-related donor cannot be found. This may be due to disadvantages such as storage costs, and the longer time sometimes needed for cord stem cells to grow and multiply after transplant, compared to adult cells. However, we don’t know if there are some patients who could benefit more from having a cord transplant instead of a different donor source.
A recent study performed by clinicians at the University of Colorado has demonstrated that, overall, transplant success is very similar for most patients when comparing cord transplants to sibling donor transplants. In fact, they were able to show that a cord transplant was a better option for patients undergoing high intensity conditioning therapy with a higher risk of relapse.
What happened in the study?
190 cord transplants were compared to 123 transplants involving a matched related donor (MRD) over an eight-year period. To determine which type of transplant was more successful, the investigators considered various clinical factors including: overall survival rates, how many patients relapsed, and the development of post-transplant complications such as GvHD and infections. They also looked to see if the type of conditioning therapy patients had pre-transplant had an impact on which type of transplant was more successful.
What did the study show?
Overall, the survival rates of patients who had a cord transplant were very similar to those who received their stem cells from a matched relative. However, significantly more cord blood recipients remained free of GvHD and relapse. This was mainly due to a decrease in the number of patients developing moderate to severe chronic GvHD, however acute GvHD cases were higher for cord blood patients too. Although it was not formally measured by the study, this would suggest that the cord blood patients may have generally experienced a better quality of life after transplant.
The results of the study were most promising for those patients who were fit and well enough to undergo full intensity (myeloablative) conditioning therapy. Cord blood patients in this group were significantly less likely to experience GvHD or relapse, although overall survival was comparable to the MRD group. Similar results were also seen for patients who had reduced intensity conditioning therapy, but the data was not statistically significant, probably because too few patients were recruited.
What does it mean for patients in the future?
Alongside other studies, this research continues to demonstrate that cord transplants are a viable option for patients with blood cancer that give similar survival rates to other stem cell sources. It also shows that for some patients who can undergo intensive condition therapy, a cord transplant might be the best possible option. Too often this type of transplant is only considered as an alternative for when a matched donor cannot be found.
The reduced levels of chronic GvHD associated with cord transplants in this study could be of significant benefit for both patients and hospital services.
Treating transplant patients who develop chronic GvHD is one of the largest costs associated with post-transplant care. Even though cord blood recipients generally need to recover in hospital for longer immediately after transplant, this is more favourable and considered a better use of limited hospital resources.
Similarly, the often painful and debilitating effects of chronic GvHD can have a huge impact on both the physical and mental wellbeing of transplant patients, which in turn reduces their quality of life.
At Anthony Nolan, our Patient Services team recognises the current need to investigate the long-term physical and mental effects GvHD and other post-transplant complications have on our patients in more detail. This ongoing work will allow us to continually adapt the services offered by the team and our clinical nurse specialist so that they meet the needs of our patients.