Types and risk groups of acute myeloid leukaemia (AML)

Types and risk groups

Doctors divide acute myeloid leukaemia (AML) is into different groups (subtypes). They use the World Health Organization (WHO) classification system.

They also divide AML into risk groups. They base your risk group on genetic changes in the leukaemia cells, and other factors. Doctors use risk groups to understand how likely it is that AML will come back after treatment.

Finding the type of AML

You have several laboratory tests using blood, bone marrow and tissue samples. The results help your doctor work out your type of AML.

Your doctor first looks at your leukaemia cells under a microscope. This is called a blood film or a blood smear. 

They also do some more detailed tests on the leukaemia cells. These include looking for:

• proteins on the surface of leukaemia cells (immunophenotyping)

• ​gene​ and ​chromosome​ changes

Immunophenotyping tests

Immunophenotyping tests look for certain proteins on the surface of the leukaemia cells. This is an important test that can quickly look at the features of each cell. It helps find out what:

• type of leukaemia you have, such as AML or another type of leukaemia

• subtype of AML you have

• risk group you are and how likely it is that the leukaemia will come back

Gene and chromosome changes

You have tests to look for gene changes (mutations)​ inside the leukaemia cells. These tests are also called chromosome analysis, cytogenetic tests or molecular analysis.

There are different types of test to look for gene and chromosome changes. These include fluorescence in situ hybridisation (FISH) testing.

Find out more about FISH testing

Next generation sequencing (NGS) is another type of test. It looks for specific changes in genes that might be causing AML. This is important in AML. Your doctor may be able to recommend treatment that targets these changes.

There are many possible genetic changes that your doctor looks for. Examples include:

• NPM1

• CEPBA

• TP53

• ASXL1

• MECOM

• NUP98

• KMT2A

Find out more about tests for AML

The World Health Organization (WHO) system

Doctors use the World Health Organisation (WHO) system to put AML into different groups. They base this on the type of myeloid cell that has become abnormal and:

• changes in the genes in the leukaemia cells

• how different the myeloid cells look under a microscope compared to normal cells - this is called differentiation

• whether the AML developed from another blood disorder called ​myelodysplastic syndrome​

Secondary myeloid neoplasms

The WHO system also considers whether the AML developed:

• after treatment for another cancer or condition

• from a fault in the genes you have inherited from your parents - this is called a germline predisposition

They group these AMLs together and call them secondary myeloid neoplasms.

The main groups of AML

The WHO system includes 3 main groups of AML:

• AML with defining genetic abnormalities

• AML defined by differentiation

• myeloid sarcoma

Each of these groups has their own subtypes. This system is quite complicated and we do not describe each subtype here. Your healthcare team can explain the type you have and what this means.

Acute promyelocytic leukaemia (APL) is a subtype of AML. The treatment of APL is different to other types of AML. We have separate information about this type of AML.

Find out about acute promyelocytic leukaemia

Risk groups for AML

Doctors also divide AML into 3 risk groups:

• favourable risk

• intermediate risk

• adverse risk

Your risk group helps doctors work out how well treatment might work. And how likely it is that your AML will come back. This helps them decide which treatment is best for you.

Risk groups depend on many factors including:

• your type of AML

• changes in chromosomes and genes

• markers on leukaemia cells

• your white blood cell count when you are diagnosed

• your age at diagnosis

• whether your AML has developed from a group of blood cancers called myelodysplastic syndrome

• whether your leukaemia is linked to treatment for an earlier cancer or condition

• whether there are any leukaemia cells in the central nervous system

Your risk group might change as you go through treatment. Your healthcare team can explain this more.

Favourable risk 

​Standard treatment​ generally works well for this risk group. You have a higher chance of your leukaemia going into ​remission​ and staying in remission. You usually have chemotherapy.

Intermediate risk 

This group has genetic and chromosomal changes that do not fit easily into the favourable and adverse groups. Doctors may look at other factors such as age and overall health to decide on treatment.

You usually have chemotherapy. You may then have more intense treatment such as a stem cell transplant. This depends on your situation and how well you respond to chemotherapy. 

Adverse risk 

This risk group has a greater risk of their leukaemia coming back (relapsing) or not responding to treatment. You usually have more intense treatment. For example, high dose chemotherapy followed by a donor stem cell transplant. You might have treatment as part of a clinical trial.

Coping and support

Coping with a diagnosis of AML can be overwhelming. It can be difficult to read about risk groups, and you may want to know more about your outlook (prognosis). We have a page about survival and AML. But many factors affect your prognosis and it is best to talk to your healthcare team about this.

Information about survival for AML

There is help and support available to help you and your friends and family cope with your diagnosis.

Go to coping and support when you have AML