A new study into an aggressive form of blood cancer, Acute Myeloid Leukemia (AML), has found it can be grouped into 11 different types. This promising discovery could help doctors predict which patients will respond to different treatments – leading to a more personalised approach to treatment and a better prognosis for a condition that currently has a poor survival rate.
AML affects around 3,000 people a year in the UK. At the moment, it can be divided into 8 sub-types based on studying the cancer cells under the microscope as well as looking for large structural changes to DNA. This new approach goes deeper – looking at the DNA within the cancer cells in minute detail.
Changes to DNA and genes within a cancer cell are what drive it to grow and multiply. The researchers studied over 100 genes associated with AML, in over 1,540 patients. The 11 types of AML each had their own genetic features, as well as symptoms.
Treatments for AML include chemotherapy, bone marrow and stem cell transplants. But many people do not respond to the treatment they are given. This finding could help explain why.
Dr Peter Campbell, from the Wellcome Trust Sanger Institute, who led the study, said:
I could have two patients who had what looked like the same leukaemia under the microscope and I could treat them with exactly the same therapy.
One of those patients would be cured and one would relapse and die very quickly. What we can see in this data-set is that clinical variability is strongly predicted by the underlying genetics.
The next steps will be to develop ways to quickly diagnose which sub-type of the condition someone has. Clinical trials will also be needed to test which treatments work best for each of the different types. The new understanding should also push forward drug development.
Dr Áine McCarthy from Cancer Research UK said:
These findings could explain why some patients’ cancer responds so well to treatment while others don’t. We need to learn more from clinical trials to find out whether tailoring treatment based on these subgroups boosts the number of people surviving the disease.
The next generation of precision medicine
Personalised or ‘precision’ medicine for cancer is not new. Breast cancer patients have their tumours checked to see if they will respond to certain drugs or hormone treatments. And other cancers have also been found to be types based on their genetics.
Precision medicines can be more effective than chemotherapy and radiotherapy as they are more targeted. They also generally have fewer side effects, as they do not kill healthy cells as well.
The idea behind precision medicine of the future is to test every patient’s tumour and find the DNA changes that are making it grow – then select a treatment that works against that tumour. However, there are concerns that some patients are missing out on the precision medicines that are already available. So there is more work to be done before this approach appears in the clinic.
But recent rapid advances in technology mean that researchers understand more than ever before about the complex DNA changes that cause cancer. This is leading to huge excitement in the medical community as it opens up new opportunities to develop the next generation of precision medicines.
Feature image via Flickr