Acute leukaemia is a cancer of the blood that can spread very quickly. Acute myeloid leukaemia (AML) affects a type of white blood cells known as myeloid cells. It most commonly affects people over the age of 65, but can occur at any age.
 
About acute myeloid leukaemia
Symptoms of acute myeloid leukaemia
Causes of acute myeloid leukaemia
Diagnosis of acute myeloid leukaemia
Treatment of acute myeloid leukaemia
 

About acute myeloid leukaemia

 
The term leukaemia refers to a group of cancers of the blood cells and bone marrow. If you have leukaemia, your white blood cells become abnormal and divide and grow in an uncontrolled way.
 
Leukaemia can be described as either acute (growing rapidly) or chronic (growing slowly). Acute leukaemia is divided into two main types – AML and acute lymphoblastic leukaemia (ALL). This factsheet focuses on AML.  
In AML, cells in your blood known as myeloid cells become cancerous. Myeloid cells are produced in your bone marrow and are responsible for producing many of the other types of cell in your blood – including red cells, white cells and platelets. AML occurs when abnormal immature myeloid cells fill up your bone marrow and prevent you producing enough of the normal blood cells.
The symptoms of AML develop rapidly and the condition quickly becomes life-threatening if not treated. According to Cancer Research UK, 2,200 people are diagnosed with AML each year.

Types of acute myeloid leukaemia

There are eight different groups or subtypes of AML. Your doctor will tell you which type of AML you have.
 
A rare type of AML is granulocytic sarcoma. This is caused when immature myeloid cells clump together outside your bone marrow to form a tumour. It can occur anywhere in your body.
Occasionally, leukaemia appears to be a mixture of AML and ALL. This type of leukaemia is known as acute biphenotypic leukaemia.

Symptoms of acute myeloid leukaemia

Symptoms of AML include:

  • feeling generally run down and weak
  • tiredness and breathlessness
  • frequent infections that don't get better
  • unusual bleeding (eg, frequent nosebleeds, heavy periods in women, bleeding from gums, or blood in your urine or faeces)
  • increased bruising, or developing a fine rash of dark red spots (called purpura)
  • fever
  • weight loss

Your symptoms can come on very quickly – over a matter of days or weeks. They may seem vague and can be confused with common illnesses such as flu.
Less common symptoms of AML include:

  • aching bones due to the pressure of too many cells being produced.
  • lumps in your skin.

These symptoms aren’t always caused by AML but if you have them, see your GP.

Causes of acute myeloid leukaemia

Doctors don’t know the exact causes of AML although much research is being done to try to find out. However, doctors do know that there are several risk factors for developing AML.

Risk factors include:

  • exposure to radiation.
  • smoking – this may account for nearly two in every 10 cases of AML.
  • exposure to certain cancer-causing substances (carcinogens) such as benzene, which is found in household paint and solvents.
  • previous cancer treatment – if you have had chemotherapy in the past, you’re slightly more likely to develop acute leukaemia, but it's important to weigh up the benefits of treating the cancer against the very small risk of developing leukaemia years later.
  • certain autoimmune conditions – such as rheumatoid arthritis, autoimmune haemolytic anaemia and ulcerative colitis (however, it’s not clear whether it is the condition or the medicine you take for it that increases your risk).
  • genetic disorders such as Down's syndrome.
  • being male – you’re slightly more likely to develop AML if you’re a man.
  • being overweight – if you have a body mass index (BMI) of 30 or above, you are slightly more at risk.
  • other blood disorders – if you have another disease of your bone marrow (eg aplastic anaemia), you are slightly more at risk.

Diagnosis of acute myeloid leukaemia

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history. If your GP thinks you may have leukaemia, he or she will ask you to have a blood test and may refer you to a haematologist (a doctor who specialises in conditions of the blood).

You will have some tests to confirm the diagnosis and investigate which type of leukaemia you have. These tests will include:

  • more blood tests 
  • bone marrow biopsy – your doctor removes a small sample of your bone marrow to be examined under a microscope
  • specific tests on the cancer cells to determine their exact nature (immunophenotyping)
  • genetic analysis of the chromosomes in the leukaemic cells (cytogenetics)
  • tissue typing – if your doctor thinks that a stem cell transplant may be an option in the future


Treatment of acute myeloid leukaemia

You may hear your doctor referring to your treatment in two phases:

  • remission induction – to get rid of the cancer with chemotherapy
  • consolidation treatment – to prevent a relapse (the cancer coming back)

Remission induction

  • Chemotherapy uses medicines to destroy cancer cells in your bone marrow. It is the main treatment used in AML. Initially, you will probably need to stay in hospital for about a month because larger doses of chemotherapy medicines are used to treat acute leukaemia than for other types of cancer.

       You will need to have a mixture of chemotherapy medicines, as this has been shown to work better than just one medicine on its own. You will usually have these different medicines in cycles, with rest periods in between.
       After   your initial treatment, you may be ‘in remission’ but this doesn’t mean you’re cured. You will need to have consolidation treatment because the cancer may return if you have a few leukaemic cells left in your bone marrow.

       If you have a type of AML known as acute promyelocytic leukaemia (APML), you may also be given a medicine called all trans-retinoic acid (ATRA) alongside your chemotherapy. ATRA is also known as tretinoin and is
       based on vitamin A. It works by making your abnormal white blood cells develop into normal cells. Side-effects of this medicine include headache, dry skin and mouth, and feeling sick.

  • Biological therapies are medicines that are manufactured to mimic or inhibit our natural body substances, such as antibodies, in order to help fight cancer cells. They target cancer cells in different ways. Gemtuzumab is a type of biological therapy known as a monoclonal antibody, which acts against certain myeloid cells. It is currently being tested in clinical trials, both in the induction and consolidation stages.

 

Consolidation treatment

 
To try to prevent AML returning after remission has been achieved, you will be given one or both of the following treatments.

  • Further courses of intensive chemotherapy.
  • Bone marrow (stem cell) transplant if you’re in general good health. This is when somebody else (preferably a brother or sister) donates healthy bone marrow or stem cells, which are transferred into your body.

New treatments

New treatments being investigated for AML include mini-stem cell transplants, cord-blood stem cell transplants, further biological therapies and new chemotherapy medicines. They are all being tested in clinical trials. Many people with leukaemia take part in clinical trials as new treatments are constantly changing. Your doctor can give you more information about clinical trials.

Published by Bupa's Health Information Team, December 2010.
 

This section contains answers to common questions about this topic. Questions have been suggested by health professionals, website feedback and requests via email.
 
What are the different classification systems used for acute myeloid leukaemia?
Should I take part in clinical trials for treatment?
What is FLT3 in acute myeloid leukaemia?
How will my treatment affect my daily life?

 

What are the different classification systems used for acute myeloid leukaemia?

AML isn’t just one disease – there are eight different groups or sub-types. By classifying your type of AML, your doctor can plan the most appropriate treatment for you.


Explanation

Doctors classify different sub-types of AML by giving each type either a name or a letter and number. This is done using one of two different systems – the French American British (FAB) system or the World Health Organization (WHO) system.

·FAB system The main way of classifying AML is using the FAB system, which separates the disease into eight sub-types. This is done using a microscope to look for changes in the blood cells taken in a sample from your bone marrow or blood.

The numbers don't mean the leukaemia you have is more or less severe.

  • M0, M1, M2 – these sub-types are called myeloblastic and make up about half of all types of AML.
  • M3 – about one in 10 people get this subtype of AML; it's called promyelocytic.
  • M4 – two in every 10 people with AML have this subtype; it's called myelomonocytic.
  • M5 – this subtype, monoblastic AML, affects between one and two in every 10 people with AML.
  • M6 – this is called erythroleukaemia and is less common.
  • M7 – this is called megakaryotic and is also less common.

·WHO system This system is important when planning treatment and predicting your response to treatment. It’s based on:

  • abnormal changes in more than one type of myeloid cell
  • chromosomal changes in the leukaemic cells – certain chromosome changes indicate a good prognosis and others a poor prognosis
  • if the leukaemia has developed from a previous blood disorder called myelodysplasia
  • any previous cancer treatment (treatment-related AML)


Should I take part in clinical trials for treatment?

You should decide with your doctor if this is the best option for you.

Explanation

Clinical trials are used to test how well a treatment works and how safe it is, before it can be made widely available to people.
There are four phases of a clinical trial.

  • Phase 1 tests a treatment to check if it’s safe, whether it has any harmful effects and at what dose the treatment should be used.
  • Phase 2 looks at how well a treatment works.
  • Phase 3 involves larger numbers of patients and investigates whether the treatment is as good as any existing treatments.
  • Phase 4 trials are carried out when a treatment has already been licensed. The aim of these trials is to get further information on side-effects, safety, risks and benefits.

New treatments aren’t always better. Sometimes treatments don't work as well or side-effects are worse than existing treatments.
Ask your doctor about the trial so you know what it involves. The Medical Research Council has some example questions you may choose to ask:

  • What’s the point of the trial? How will it help people?
  • Who is taking part in it?
  • If the trial is testing a drug, how often must I take it, when and for how long?
  • Do you know anything about the potential side-effects, risks or benefits?
  • How will the trial affect my daily life?
  • How often will I have to visit the clinic?
  • What will happen at these visits? Will I have extra tests?
  • What other medication can I take when I’m taking part in this trial?
  • What happens if my condition gets worse?

What is FLT3 in acute myeloid leukaemia?

FLT3 is a protein that is found on the surface of white blood cells. If this protein has changed (mutated), it may increase your risk of relapse (leukaemia coming back).

Explanation

The FLT3 protein makes white blood cells multiply and produce other cells if a certain chemical, called growth factor, stimulates it. Growth factor is regulated in our bodies to ensure cells grow and multiply in a controlled way. If the FLT3 mutates and doesn't work properly, it can cause the cells to grow and multiply uncontrollably.

In one in three people with AML and one in 20 people with ALL, there is a problem with the FLT3 protein. It is said to have mutated or changed. Research has shown that people with this mutation are less likely to go into remission (have their leukaemia controlled) and are more likely to have a relapse (the leukaemia isn't controlled and comes back).

Medicines called FTL3 inhibitors that try to target this protein are being tested in clinical trials to try to prevent relapse and increase remission rates.

How will my treatment affect my daily life?

This depends on your usual activities and how you react to the type of treatment you have.

Explanation

During the period when you’re having repeated courses of intensive chemotherapy, much of your time will be spent in hospital with only short breaks in between. During these breaks you may feel very tired, which can affect how you cope with your daily activities such as cleaning and going shopping. Most people who have chemotherapy say that tiredness is the most disruptive and frustrating side-effect of the treatment. Even after resting, you may still feel very tired. Your energy levels should get back to normal around six months to a year after treatment but this can be longer in some people.

Ask for support and help from your family and friends to help you cope with your daily routine. Also make sure that you do some gentle exercise, eat a healthy diet and get plenty of rest when you need it to help you cope with tiredness.

If you have a bone marrow or peripheral stem cell transplant, you will need to go into hospital several times, which will affect your usual routine. Ask your doctor to explain what will happen to you and how long you may have to stay in hospital. When you’re in hospital, you will need to avoid contact with anyone who may have an infectious illness. You will also need to avoid eating certain foodstuffs, such as eggs or takeaways, which may be undercooked or contaminated.

It usually takes at least one year before you will begin to feel like your old self and you may want to talk to your school or work about going back only part time.
 
Keywords: acute myeloid leukaemia, leukaemia, leukemia, AML, FAB system, clinical trial, FLT3

Further information

Sources

·Acute myeloid leukaemia. Cancer Research UK. www.cancerhelp.org.uk, published August 2010
·Acute myeloid leukaemia. Macmillan Cancer Support. www.macmillan.org.uk, accessed 28 July 2010
·Acute myeloid leukaemia, adult (AML). Leukaemia & Lymphoma Research. www.beatbloodcancers.org, accessed 28 July 2010
·What are the risk factors for acute myeloid leukemia? American Cancer Society. www.cancer.org, accessed 28 July 2010
·Scélo G, Metayer C, Zhang L, et al. Household exposure to paint and petroleum solvents, chromosomal translocations, and the risk of childhood leukemia; Environmental Health Perspectives. 2009;117(1):133–9
·Guidelines on the management of acute myeloid leukaemia in adults, British Committee for Standards in Haematology, 2006. www.bcshguidelines.com.

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This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
Publication date: December 2010
 
 

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