WASHINGTON, June 8 (Xinhua) -- Acute myeloid leukaemia (AML), an aggressive form of the blood cancer, is not a single disorder, but at least 11 different diseases at the genetic level, a study said Wednesday.
The study, published in the New England Journal of Medicine, may explain differences in survival among young AML patients and help improve clinical trials and the way patients are diagnosed and treated in the future.
"Two people may have what looks like the same leukaemia down the microscope, but we find extensive differences between those leukaemias at the genetic level," said Peter Campbell, one of the leaders of the study from Britain's Wellcome Trust Sanger Institute.
"These genetic differences can explain so much of why one of those patients will be cured, while the other will not, despite receiving the exact same treatment," Campbell said.
In what was called a "landmark" and "ground-breaking" study, researchers studied 1540 patients with AML that were enrolled in clinical trials and analysed more than 100 genes known to cause leukaemia to identify common genetic themes behind the development of the disease.
The researchers found that the patients were divided into at least 11 major groups, each with different constellations of genetic changes and distinctive clinical features.
Despite finding common themes, the study also showed that most patients had a unique combination of genetic changes driving their leukaemia.
This genetic complexity helps explain why AML shows such variability in survival rates among patients, they said.
"We have shown that AML is an umbrella term for a group of at least 11 different types of leukaemia," said Campbell. "We can now start to decode these genetics to shape clinical trials and develop diagnostics."
AML is an aggressive blood cancer that develops in cells in the bone marrow and affects people of all ages, often requiring months of intensive chemotherapy in hospital. Worldwide, more than 350,000 people were estimated to have AML in 2012.