Detailed genetic analysis into Acute Myeloid Leukaemia (AML) has found that it is 11 distinctive diseases, rather than just one.

The study, which was published in the New England Journal of Medicine, discovered that the reason some patients respond more positively to treatment than others could be explained by genetic differences. The researchers conducting the study believe these findings should help in clinical trial development and Cancer Research UK says this type of study provides new insights into the disease.

In Britain, there are around 3,000 new cases of AML every year. It is often aggressive, especially in older patients, and overall survival rate is around 20% after five years.

ASL is predominantly treated through stem-cell transplantation and chemotherapy, but it’s often difficult to tell how patients will respond.

Currently, clinicians rely on analysis under a microscope and checks for chromosomal abnormalities. This study involved more than 1,500 ASL patients and researchers conducted a far more detailed genetic analysis into the disease. They studied more than 100 genes known to cause leukaemia and examined how they interacted.

The researchers discovered that the patients divided into a minimum of 11 major groups, each with their own set of clinical features and genetic changes. Co-leader of the research, Dr Peter Campbell from the Wellcome Trust Sanger Institute, said the findings would help doctors make meaningful predictions about the outcome for patients.

He said two patients could have what appeared to be the same leukaemia under the microscope and be treated in exactly the same way, but one could be cured and the other could relapse. The new data shows that clinical variability is predicted strongly by fundamental genetics.

Fellow co-author Dr Elli Papaemmanuil said the findings dig deeper into the causes of AML. She said that understanding these paths can help to develop more suitable treatments for individual AML patients.

The findings have been welcomed by Dr Áine McCarthy from Cancer Research UK, who said that this kind of science continues to provide new insights into cancer, which can help Britain beat cancer. She concluded that more needs to be learned from clinical trials to find out whether tailoring treatment to each subgroup boosts the survival rate.