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Acute Myeloid Leukaemia
Acute myeloid leukaemia is a
rare type of cancer, affecting approximately 2,000 adults and 50 children per
year in the UK.
Leukaemia is a cancer of the white blood cells (phagocytes) Acute myeloid leukaemia is an overproduction of immature myeloid white blood cells. The immature cells are sometimes referred to as blast cells. Normally, white blood cells repair and reproduce themselves in an orderly and controlled way. In leukaemia, however, the process gets out of control and the cells continue to divide, but do not mature. These immature dividing cells fill up the bone marrow and prevent it from making healthy blood cells. As the leukaemia cells do not mature, they cannot work properly, which leads to an increased risk of infection. As the bone marrow cannot make enough healthy red blood cells and platelets, symptoms such as anaemia and bruising also occur. Acute myeloid leukaemia can affect adults of all ages, but is more common in older age groups. It is rare in people under 20. What are the causes of acute myeloblastic leukaemia?The exact causes of acute myeloid leukaemia are unknown. Research into possible causes is going on all the time. In very rare cases, leukaemia may occur after exposure to chemicals such as benzene, formaldehyde and other solvents used in industry. Large doses of radiation and some drugs used to treat other cancers may also rarely cause leukaemia, many years after people have received them. People exposed to high levels of radiation due to atomic bomb explosions or nuclear industry accidents are more likely to develop leukaemia than people who have not been exposed to radiation. People with certain blood disorders (such as myelodysplastic syndrome) or some genetic disorders, including Down's syndrome, are known to have a higher risk of developing leukaemia. What are the symptoms of AML?The main symptoms of acute myeloid leukaemia are caused by the increased number of immature white cells (blast cells) in the bone marrow, which reduces the production of normal blood cells. The main signs and symptoms are: Anaemia (a lack of red blood cells), which can cause people to look pale, feel very tired and sometimes breathless at the slightest effort. Feeling generally unwell and run down - this may be caused by anaemia or repeated infections. Repeated infections - for example, a sore throat or sore mouth caused by a lack of white blood cells. Aching joints and bones - bones may be affected by leukaemia cells. Unusual bleeding
caused by a reduction in the number of platelets. This may include bruising
(bruises may appear without any apparent injury), bleeding gums, frequent
nosebleeds, and heavy periods in women. As well as bruising more easily than
normal, a particular type of bruising can be seen. This consists of small
blood-like spots called Rarely, areas of the skin or gums may be affected by the leukaemia cells. The affected areas can appear sore and take a long time to heal.How is it diagnosed?Usually you begin by seeing your doctor who will examine you and take a blood test. If the results of the test are abnormal in any way, your doctor will refer you to hospital for advice and treatment from a doctor who specialises in the treatment of blood problems (known as a haematologist). At the hospitalMost people with AML are referred for treatment at a specialist haematology unit where a group of specialist doctors work together. This is known as a multidisciplinary team and includes one or more haematologists, a medical oncologist (chemotherapy specialist) and a clinical oncologist (radiotherapy specialist). The team will also include specialist nurses, social workers, dieticians and physiotherapists. The doctor at the hospital will take your full medical history before doing a physical examination and a more specific blood test, which checks the numbers of all the different types of blood cell. If the blood test shows that leukaemia cells are present, your doctor will want to take a sample of your bone marrow. This is the most important test for finding out if you have leukaemia, and gives information that the doctors need to plan the best treatment for you. Bone marrow sample/biopsyA sample of bone marrow is taken from the back of your hipbone (pelvis) or, less commonly, the breastbone (sternum). It is looked at under a microscope by a pathologist to see if it contains any abnormal white blood cells. The pathologist will be able to tell which type of leukaemia it is by identifying the type of abnormal white cell. The bone marrow sample is taken under a local anaesthetic. You are given a small injection to numb the area and a needle is passed gently through the skin into the bone. A small sample of the marrow is drawn out into a syringe for examination under the microscope. The test can be done on the ward or in the outpatients department. The whole procedure takes about 15 minutes. It may be uncomfortable but it only lasts a short time as the marrow is drawn into the syringe. Some hospitals give a short-acting sedative which makes you feel drowsy or sleepy while the biopsy is taken. Sometimes a small core of
marrow is needed (a trephine biopsy). This procedure takes a Your doctor may ask you to have further tests, which may include a chest x-ray to check that your lungs and heart are healthy. CytogeneticsWithin each cell of the body are chromosomes which are made up of genes. The genes control all activities of the cell. In myeloid leukaemia there are often changes in the structure of the chromosomes within the leukaemic cells, but not the normal cells of the body. The tests on the blood and bone marrow sample will include a chromosome analysis to look for any particular changes in the chromosomes. These tests, known as cytogenetic tests, can help to decide on the best treatment and predict how well the leukaemia may respond to that treatment. Classification of AML There are several classification systems that break AML down into various sub-types. The most commonly used system in the UK is the French-American-British (FAB) system. FAB classification of acute myeloid leukaemia
M0
Acute myeloid leukaemia with minimal evidence of myeloid differentiation These terms describe the exact type of cell that is being overproduced and the stage of development (maturation) of the leukaemia cells. The blood and bone marrow samples will be checked by haematologists and pathologists to find out which type of leukaemia it is. They will look to see exactly which type of cell has become leukaemic and at which stage of their development. The cells may also be tested with antibodies for specific proteins on their surface. This process is known as immunohistiotyping. The genetic make-up of the leukaemia cells will also be examined, as the different types are associated with particular genetic changes. Knowing the exact type of leukaemia, from the results of the cytogenetics tests, helps the doctors to know which treatment is likely to be most effective in treating the leukaemia. Treatment The aim of treatment for acute myeloid leukaemia is to destroy the leukaemia cells and allow the bone marrow to work normally again. When there is no sign of the leukaemia it is known as remission. Types of treatment
Chemotherapy is the main treatment used, as research has shown that certain
types of chemotherapy drugs can be very effective in treating AML. Most patients
with acute myeloid leukaemia go into remission after chemotherapy and more and
more people are being cured. People who have promyelocytic AML (type M3) will also be treated with a drug called ATRA (all trans-retinoic acid). It is a specialised form of vitamin A and is also known as tretinoin (Vesanoid(r)). ATRA is given for up to three months alongside chemotherapy treatment as it makes the leukaemic cells mature (differentiate) and so can reduce the leukaemic symptoms very quickly. See page 29 for more information about ATRA. Your doctor will plan your treatment by taking into account a number of things, including your age, general health, and the type of genetic abnormality present in the leukaemia cells. Some
people have a greater risk of the leukaemia not going into remission or of
coming back after treatment. This is known as high-risk AML. Factors which make
the leukaemia less likely to respond to treatment, or to come back, include:
The treatment for people with 'high-risk leukaemia' may vary slightly from people who do not have these factors. A research trial (AML-HR) is currently being carried out to test new types of treatment against the standard treatments for high-risk AML and your doctor may ask you whether you want to enter the trial. People over 60 with AML may be asked to consider taking part in a research trial to see whether more intensive chemotherapy is more effective in treating the leukaemia than less intensive chemotherapy. The trial is known as AML-14. Many people who are under 60 with AML may be asked if they would like to take part in the AML-15 trial, which is comparing the effectiveness of the current treatments used for AML. You will be given detailed information about any trial in which you are invited to take part. The main treatment for AML is chemotherapy. Some people may also go on to have high-dose chemotherapy with a stem cell or bone marrow transplant You may find that other people with leukaemia at the hospital are having different treatment from you. This may be because their illness takes a different form, so they have different needs. If you have any questions about your own treatment, don't be afraid to ask your doctor or nurse. It is often useful to make a list of questions for your doctor and to take a close friend or relative with you. Some people find it reassuring to have another medical opinion to help them decide about their treatment. Most doctors will be pleased to refer you to another specialist for a second opinion, if you feel this will be helpful. However, this can sometimes take time to arrange and may mean that the start of your treatment is delayed, which may not be advisable. Usually treatment for AML should be started as soon as possible. Giving your consent Before you have any treatment your doctor will explain the aims of the treatment and you will usually be asked to sign a form saying that you give your permission (consent) for the hospital staff to give you the treatment. No medical treatment can be given without your consent, and before you are asked to sign the form you should have been given full information about:
If you do not understand what you have been told, let the staff know straight away so that they can explain again. Treatments for leukaemia can be complex, so it is not unusual for people to need repeated explanations. It is often a good idea to have a friend or relative with you when the treatment is explained, to help you remember the discussion more fully. You may also find it useful to write down a list of questions before you go for your appointment. Patients often feel that the hospital staff are too busy to answer their questions, but it is important for you to be aware of how the treatment is likely to affect you and the staff should be willing to make time for you to ask questions. You can always ask for more time to decide about the treatment, if you feel that you can't make a decision when it is first explained to you. You are also free to choose not to have the treatment, and the staff can explain what may happen if you do not have it. If AML is not treated, people usually live only for a few weeks. It is important to tell a doctor, or the nurse in charge, about your decision immediately so that your decision can be recorded in your medical notes. The benefits and disadvantages of treatment Many people are frightened at the prospect of cancer treatments, particularly because of the potential side effects. Some people ask what would happen if they did not have any treatment. Although many of the treatments can cause side effects, knowledge about how these treatments affect people and improved ways of reducing or avoiding many of these problems, have made most of the treatments much easier to cope with. Treatment can be given for different reasons and the potential benefits will vary depending upon the individual situation. In people with AML, chemotherapy is usually done with the aim of curing the cancer. Occasionally additional treatments, such as high-dose chemotherapy with stem cell or bone marrow transplants, are also given to reduce the risks of it coming back. If the leukaemia has returned after initial treatment, more treatment may be given to get the leukaemia into remission again. If the leukaemia is at a more advanced stage, the treatment may only be able to control the disease, leading to an improvement in symptoms and a better quality of life. However, for some people in this situation the treatment will have no effect upon the leukaemia and they will have the side effects without any of the benefit. If you have been offered treatment that is intended to cure the leukaemia, the decision whether to accept treatment may not be a difficult one. However, if a cure is not possible and the treatment is being given to control the leukaemia for a period of time, it may be more difficult to decide whether to go ahead with treatment or not. Making decisions about treatment in these circumstances is always difficult, and you may need to discuss in detail with your doctor whether you wish to have treatment. If you choose not to, you can still be given supportive (palliative) care, with medicines to control any symptoms. |
petechiae,
usually seen on the legs or in the mouth.
