Myeloid Leukaemia

Myeloid leukaemia is a type of blood cancer that begins in the bone marrow and affects blood cells. It develops rapidly and requires urgent treatment, but newer treatments are helping more people live longer with this condition.

Table of contents

• What is myeloid leukaemia?
• Types of myeloid leukaemia
• Who is affected by this disease?
• What causes myeloid leukaemia?
• Symptoms of myeloid leukaemia
• How is it diagnosed?
• Treatment
• Living with myeloid leukaemia

What is myeloid leukaemia?

Myeloid leukaemia is a type of cancer that affects your blood and bone marrow. Your bone marrow is the soft, spongy tissue inside most of your bones where blood cells are made^[2]. This cancer is called “myeloid” because it affects cells that normally develop into certain types of blood cells, including red blood cells, white blood cells, and platelets^[4].

In myeloid leukaemia, the bone marrow produces abnormal, immature white blood cells called myeloblasts or blasts. These abnormal cells don’t work properly and build up in your blood and bone marrow^[2]. As they increase in number, there is less room for healthy blood cells. This leads to problems like easy bleeding, anaemia (low red blood cell count), and frequent infections^[6].

The most common form is acute myeloid leukaemia (AML), which is aggressive and progresses quickly. The word “acute” means the disease tends to get worse rapidly if not treated^[4]. Without treatment, AML can be life-threatening, which is why treatment usually needs to begin within days of diagnosis^[9].

• Bone marrow
• Blood

Types of myeloid leukaemia

There are several subtypes of myeloid leukaemia. They all affect your blood cell levels, but different types cause different symptoms and respond to treatment in different ways^[2].

Doctors identify which subtype you have by examining cancerous cells under a microscope. They also look for changes in your chromosomes and mutations in certain genes^[2].

The main subtypes include^[2]:

• Myeloid leukaemia: Cancer in cells that produce neutrophils, a type of white blood cell. Most people with AML have this subtype.
• Acute monocytic leukaemia (AML-M5): Cancer in cells that produce monocytes, another type of white blood cell.
• Acute megakaryocytic leukaemia (AMLK): Cancer in cells that produce red blood cells or platelets.
• Acute promyelocytic leukaemia (APL): Cancer in promyelocytes (immature white blood cells) that prevents these cells from developing properly.

Most AML subtypes are categorized based on how developed the cancer cells are at the time of diagnosis, and how different they are from normal cells^[6].

Who is affected by this disease?

Acute myeloid leukaemia is a rare type of cancer. In the UK, around 3,100 people are diagnosed with it each year^[9]. In the United States, it affects about 4 in 100,000 adults annually, with approximately 1,160 children receiving an AML diagnosis each year^[2].

AML is the most common type of acute leukaemia in adults^[4]. It typically affects people age 60 and older, but it can also affect younger adults and children^[2]. The risk of developing AML increases with age, and it is most common in people over 75^[9].

What causes myeloid leukaemia?

Doctors aren’t sure exactly what causes acute myeloid leukaemia. In most cases, there is no identifiable cause^[4]. What they do know is that the condition happens when certain genes or chromosomes mutate (change), creating abnormal blood cells^[2].

These genetic changes may happen in three different ways^[2]:

• During your lifetime when something changes your DNA
• If you inherited a genetic disorder that increases your risk of developing AML
• If there was a change in certain genes in your biological parents’ sperm or egg

Certain factors can increase your risk of getting AML, including^[4][6]:

• Previous chemotherapy or radiotherapy: Having had chemotherapy or radiation therapy to treat another cancer
• Smoking: Especially after age 60
• Exposure to radiation: Including previous radiotherapy treatment
• Chemical exposure: Exposure to benzene, a chemical used in manufacturing that’s also found in cigarette smoke
• Blood disorders: Having a blood disorder such as myelodysplastic syndrome
• Genetic conditions: Some genetic conditions, such as Down’s syndrome, increase risk
• Treatment for other leukaemias: Treatment for acute lymphoblastic leukaemia (ALL) as a child

Being male also increases your risk of AML^[7].

Symptoms of myeloid leukaemia

The symptoms of AML usually develop over a few weeks and become worse over time^[9]. Early on, symptoms may feel like you have a cold or flu that won’t go away^[2]. Because AML is aggressive, you quickly develop new and more noticeable symptoms.

Common symptoms include^[2][4][9]:

• Feeling very tired or weak
• Looking pale or “washed out”
• Fever and night sweats
• Frequent infections or infections that don’t go away
• Easy bruising or bleeding, including frequent nosebleeds and bleeding gums
• Shortness of breath
• Dizziness
• Headaches
• Loss of appetite and unexplained weight loss
• Swollen lymph nodes
• Bone, back, or abdominal pain
• Feeling cold
• Tiny red spots on your skin called petechiae, caused by bleeding under the skin
• Wounds or sores that don’t go away

If you or your child have symptoms that worry you, you should speak to your doctor. Although it’s highly unlikely that leukaemia is the cause, these symptoms should be investigated^[9].

How is it diagnosed?

If your doctor thinks you may have leukaemia, they will arrange blood tests to check your blood cells^[9]. Most people start by seeing their GP if they have symptoms, although some people may go to accident and emergency depending on their symptoms^[5].

Tests that examine the blood and bone marrow are used to diagnose AML^[6]. These include:

Blood tests: A complete blood count (CBC) measures the number of blood cells in a sample of your blood. The results may show too many or too few white blood cells, and often find that there are not enough red blood cells and platelets. Another blood test looks for immature white blood cells called myeloblasts in the blood^[6].

Bone marrow tests: These involve removing a sample of bone marrow and bone for testing. There are two main types—bone marrow aspiration and bone marrow biopsy^[7][14]. During a bone marrow aspiration, a healthcare professional uses a thin needle to remove a small amount of liquid bone marrow, usually taken from a spot in the back of the hip bone. The samples are sent to a lab where they are examined under a microscope.

Genetic tests: These tests look for gene and chromosome changes that can help determine which subtype of AML you have and help guide treatment decisions^[7].

If you are diagnosed with AML, you may have additional tests to see whether the cancer has spread. These include imaging tests and a lumbar puncture, which is a procedure to collect and test cerebrospinal fluid (the fluid around your brain and spinal cord)^[7].

Treatment

Treatment for AML needs to begin as soon as possible, as it can develop quickly^[9]. Treatment is often carried out in two main stages or phases^[12][16]:

Induction: This is the first stage of treatment. It involves intense chemotherapy with the goal of killing as many leukaemia cells in your blood and bone marrow as possible. The aim is to bring about a complete remission, which means that the signs and symptoms of cancer are reduced or have disappeared^[12][16].

During induction, you will usually be given a combination of two or more chemotherapy medicines. The treatment will be carried out in hospital or in a specialist centre, as you’ll need very close medical and nursing supervision^[12]. You’ll have regular blood transfusions because your blood will not contain enough healthy blood cells, and you’ll be vulnerable to infection^[12].

Consolidation: This second phase is also called post-remission therapy. The goal is to continue to rid the body of leukaemia cells that remain after induction, maintain complete remission, and prevent the cancer from coming back^[12][16]. Consolidation usually involves chemotherapy or a stem cell transplant.

Some people may also have a third phase called maintenance therapy. This involves chemotherapy at a lower strength and for a longer period of time^[16].

Chemotherapy is the main treatment for AML^[9]. It uses medicines to kill cancer cells. The chemotherapy medicines are usually injected into a thin tube that’s inserted either into a blood vessel near your heart or into your arm^[12].

If your doctors do not think you’re fit enough to withstand the effects of intensive chemotherapy, they may recommend non-intensive treatment. This involves using an alternative type of chemotherapy that is given at a lower dosage^[12].

Other treatments may include^[9][12]:

• Targeted cancer drugs: These are medicines that target specific changes in cancer cells
• Stem cell or bone marrow transplant: This treatment involves intensive chemotherapy and sometimes radiotherapy, followed by a transplant of healthy stem cells
• Radiotherapy: This uses high doses of controlled radiation to kill cancerous cells. It may be used to prepare the body for a transplant or to treat advanced cases

Side effects of treatment are common and can include feeling or being sick, bruising or bleeding easily, diarrhoea, loss of appetite, sore mouth and mouth ulcers, tiredness, skin rashes, and hair loss^[12]. Most side effects should resolve once treatment has finished. Tell a member of your care team if side effects become particularly troublesome, as there are medicines that can help.

Living with myeloid leukaemia

Recovering from AML isn’t the same as recovering from other illnesses. It can take several months to rebuild your fitness after treatment ends^[21]. You will have check-ups with your medical team regularly after treatment. At first, this could be several times a week, but eventually the check-ups will become less frequent^[21].

Taking care of yourself: It’s important to take good care of yourself during and after treatment. Eating a healthy diet with fruits, vegetables, lean proteins, and whole grains can help you feel stronger and speed your recovery^[22][24]. Drink plenty of fluids to stay hydrated, especially if you have side effects like vomiting or diarrhoea.

Staying as active as possible will give you more energy and help fight fatigue^[22][24]. Ask your doctor how to exercise safely. You might only be able to walk for a few minutes at a time at first, but gradually increase the length and intensity of your workouts as you feel ready.

Emotional wellbeing: Living with cancer can bring up many different feelings. You might feel shocked, upset, frightened, uncertain, confused, angry, or sad^[19]. These feelings may come and go, leaving you feeling exhausted. It’s natural to experience different emotions when you are coming to terms with your diagnosis.

Try to talk to your friends and family about what is happening and how you feel^[19]. This can also help them support you. Get in touch with your doctor or specialist nurse if you are worried about any symptoms.

Many people with AML are diagnosed with low-risk disease that is treatable, and their doctor might tell them that they can expect to have the same length of life as people without AML^[19]. However, chronic cancers like myeloid leukaemia will always be part of your life, and it can be difficult to adjust to this reality^[19].