An OICR-supported discovery could help acute myeloid leukemia (AML) patients get earlier, more personalized treatments to slow down deadly relapses.
A routine test that’s already performed after stem cell transplants can identify patients whose leukemia is likely to return and get them treated sooner, according to new OICR-supported research.
Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults. It’s an aggressive disease, which is most effectively treated by a stem cell transplant.
About 60 per cent of transplant recipients will be cured of AML, but the 40 per cent who aren’t cured will often see cancer return more aggressively.
That sparked a group of Hamilton-based researchers led by Dr. Michael Radford and Dr. Tobias Berg to look for ways to detect signs of AML relapse. Their findings, published in Transplantation and Cellular Therapy, show that a commonly used test measuring the ‘DNA footprint’ of blood cells can give a good indication of a patient’s chances of relapse as early as 30 days after a transplant.
“This is really exciting because the test is a strong predictor of AML relapse very early on, when we can take action to wipe out the disease,” says Berg, Associate Professor of Oncology at McMaster University and the study’s senior author.
AML originates in blood stem and progenitor cells, and while it can sometimes be treated with chemotherapy alone, a stem cell transplant is often a patient’s best chance at a cure. In a successful transplant, the recipient’s blood cells (including its immune cells) are completely replaced by healthy donor cells, some of which can help keep the cancer away.
But new blood cells don’t always replace all the old ones, and they can sometimes co-exist in a patient’s blood, known as ‘mixed chimerism’.
Berg and colleagues looked at DNA test results 30, 60 and 90 days after AML patients received stem cell transplants then followed patients’ outcomes going forward. They found that patients who still had mixed chimerism in those tests were much more likely to relapse.
While chimerism testing is already used in Ontario after stem cell transplants, it’s use and application are varied. The scientists behind this study hope their findings will lead to wider use of chimerism testing to identify AML patients at risk of relapse and trigger further treatment for those who are.
This study on chimerism is part of a larger area of work supported by OICR’s Clinical Translation Pathway. Berg and colleagues also explored tests predictive tests that look for microscopic traces of tumours after treatment — known as minimum residual disease — as well as maintenance strategies to prevent and treat AML relapse in patients identified as high risk. “This work is the result of a strong collaboration, both across Hamilton and across Ontario,” Berg says. “We’re grateful for OICR’s support, which helped bring us all together.”
