A simple blood test capable of detecting trace levels of leukemia cells remaining after intensive chemotherapy has been developed by scientists at the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London. The research was co-funded by the NIHR Programme Grants for Applied Research Programme and the blood cancer charity Bloodwise. The study was conducted within the National Cancer Research Institute (NCRI) AML17 clinical trial, which treated patients from across the UK, Denmark and New Zealand.
Acute myeloid leukemia (AML) is diagnosed in around 2,400 people each year in the UK. Although survival rates are extremely poor overall, outlook for younger patients able to tolerate intensive treatment is better, with over half of patients under 40 years old surviving for at least five years.
In research published online in the New England Journal of Medicine, scientists used a ‘minimal residual disease’ (MRD) test to predict relapse. The patients all had AML driven by faults in the NPM1 gene – which is the most common genetic sub-type of the disease and accounts for a third of all cases.
The best chance of a cure involves chemotherapy and, in the case of high risk patients, a stem cell transplant. While intensive treatment is normally successful in sending the cancer into remission, relapse is very common. Patients usually only undergo a stem cell transplant after chemotherapy if they are judged to be at high-risk of relapse and are fit enough.
The researchers found that MRD testing was far superior at predicting relapse compared to current methods, which mainly rely on analysis of genetic abnormalities within individual patients’ cancer cells that influence whether they are ‘high risk’ or ‘low risk’ at the start of treatment. All samples analyzed using MRD testing were from patients determined to be at ‘standard risk’ of relapse using existing testing.
Life Sciences Minister George Freeman MP said:
“This ground-breaking study has the potential to have a major impact on the treatment for patients suffering this devastating condition. It is studies such as this which highlight the importance of the government’s commitment to health research and collaboration with research charities. These exciting developments are being made possible thanks to our investment of more than £1 billion a year through the National Institute for Health Research.”
Professor David Grimwade, Principal Investigator at the NIHR BRC at Guy’s and St Thomas’ and King’s College London who led the research, said:
“Conventional methods for guiding treatment for this aggressive type of leukemia are inadequate. The MRD test is an invaluable tool to assess treatment response and identify those patients for whom chemotherapy is not sufficient and require stem cell transplantation or new treatments.”
Alasdair Rankin, Director of Research at Bloodwise, said:
“Treatment for acute myeloid leukemia is highly toxic and survival rates are desperately poor, particularly for older patients. Preemptive treatment to prevent relapse in those most at risk would reduce the levels of toxic treatment needed and improve its chances of success.”