One of the most prevalent forms of blood cancer, acute myeloid leukaemia (AML), is actually 11 distinct diseases, say researchers.
Scientists made the discovery after detailed genetic analysis of the disease from 1,540 patients undergoing clinical trials.
"These genetic changes clustered into 11 subtypes which responded differently to the two main treatments for leukaemia: intensive chemotherapy and stem cell transplantation," the Financial Times reports.
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AML is a highly aggressive form of blood cancer and while most patients respond well to chemotherapy in the short term, the relapse rate is particularly high.
"Only 20 per cent survive for five years or more and no new treatments have been introduced for at least 20 years," says Matt Kaiser, of cancer research charity Bloodwise.
Study co-author Peter Campbell, of the Wellcome Trust Sanger Institute, told the BBC the findings could help patients receive a far more tailored treatment regimen.
"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," he said. "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 that clinical variability is strongly predicted by the underlying genetics."
Nearly 3,000 people were diagnosed with AML in the UK in 2013, the last year for which figures are available. "While the condition is most common in those over the age of 65, individuals of any age can be affected," says The Guardian.
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