Chronic Myeloid Leukaemia

Chronic myeloid leukaemia is a type of blood cancer which develops when the body has too many abnormal white blood cells, known as granulocytes.

Last modified: February 25, 2022

Quick facts about chronic myeloid leukaemia Quick facts

  • Chronic myeloid leukaemia (CML) starts when the bone marrow produces an excess of white blood cells that grow and spread abnormally
  • These white blood cells are called granulocytes. They are a type of myeloid blood cell that move through a large network of tissues and organs called the lymphatic system and impact areas such as the lymph nodes, spleen and liver
  • Chronic leukaemia can develop slowly and may take months or years for symptoms to develop
  • CML is a rare type of chronic leukaemia, with 376 Australians estimated to have been diagnosed in 2021
  • Adults over the age of 40 account for nearly 70% of all CML cases in Australia

Types of chronic myeloid leukaemiaTypes of chronic myeloid leukaemia

All cases of CML have a chromosomal abnormality called the Philadelphia chromosome.  Your cells contain 23 chromosomes and the Philadelphia chromosome develops in chromosome 22 when part of chromosome 9 joins onto it. This new type of chromosome contains the BCR-ABL gene that tells leukaemia cells to grow and spread.

Signs and symptoms of chronic myeloid leukaemiaSigns and symptoms

As signs and symptoms for CML can be similar to other common conditions, it’s important to see your GP or healthcare professional if you experience any of the symptoms below. In many cases, these symptoms may not show for months or years after developing CML. Discussing anything concerning with your doctor as soon as possible can help give you peace of mind and offer the best chance of successful treatment if you receive an CML diagnosis.

Although CML has no symptoms in many cases and is often diagnosed during routine blood tests, symptoms may include:

  • Tiredness

  • Anaemia, including dizziness, paleness and shortness of breath

  • Night sweats

  • High temperature

  • Unexplained weight loss and loss of appetite

  • Bone pain

  • Enlarged abdomen and feeling full after eating a small amount

  • Increased bleeding and bruising 

Stages of chronic myeloid leukaemia Stages

Unlike other cancers, CML is classified into phases rather than stages. These phases are based on the number of immature white blood cells in your bone marrow and blood. 

Chronic phase

This phase can last many years and is when most people are diagnosed. During this phase the blast cell (immature cells) numbers in the blood and bone marrow are low (< 5%), which means the phase is relatively stable. There are few (if any) symptoms in this stage.

Accelerated phase

During the accelerated phase, the number of blast cells start to increase in the bone marrow and blood.

Blast phase

The blast phase is a period of rapid progression where blast cell numbers in the blood and bone marrow increase quickly. Symptoms often worsen and the patient is considered to have a form of acute leukaemia.

Treatment for chronic myeloid leukaemia

There are many different types of treatment for chronic myeloid leukaemia. Your treatment will depend on you and your cancer.

Frequently asked questions about chronic myeloid leukaemia FAQs

Is chronic myeloid leukaemia hereditary?

CML is not hereditary. Although genetic abnormalities can cause CML, these are not passed down from parents and instead occur during your lifetime. 

What causes chronic myeloid leukaemia?

The causes of CML are not fully known. However, there are some factors which contribute to the risk of CML developing, including: 

  • Age – Nearly 70% of all cases of CML are diagnosed in adults over the age of 40
  • Gender –Men are more likely to develop CML than women
  • Genetic abnormalities – Nearly all people with CML have a genetic abnormality known as the Philadelphia chromosome. It contains the BCR-ABL gene that tells leukaemia cells to grow and spread. The Philadelphia chromosome is not inherited and cannot be passed down
  • Exposure to radiation and certain chemicals – Exposure to high doses of radiation and benzene, as well as some chemotherapy treatments increase your risk of developing CML 
How common is chronic myeloid leukaemia?

Leukaemia is less common than other cancer types, affecting 1 in 61 Australians by the age of 85. CML is a rare type of chronic leukaemia. In 2021 there were 376 cases of CML, with more males than females diagnosed.

How is chronic lymphocytic myeloid diagnosed?

There are many different tests that are used to diagnose CML, alongside a physical examination. This includes blood tests and a bone marrow biopsy.  The Philadelphia chromosome can be detected in blood or bone marrow, and a DNA-based test called BCR-ABL1 will be performed at diagnosis and monitored throughout your treatment. You may also receive an ultrasound to identify if your spleen has been affected. 

What is the difference between chronic myeloid leukaemia (CML) and chronic lymphocytic leukaemia (CLL)?

CML and CLL are two forms of chronic leukaemia which develop from different types of white blood cells. CML develops from myeloid cells called granulocytes, while CLL develops from lymphocytes such as B-cells and T-cells. 

What can I do to decrease my risk of chronic myeloid leukaemia?

There are no known ways to prevent CML. However, there are a number of lifestyle-related factors you can consider to reduce your risk of developing cancer overall, like:

  • Avoiding high doses of radiation and certain chemicals
  • Getting regular exercise – Cancer Australia recommends at least 30 minutes of moderate-intensity exercise each day
  • Eating a healthy, balanced diet – Eat a fibre-rich diet from grain and legume sources, as well as enjoy a variety of fruit (2 serves) and vegetables (5 serves) per day, limit your intake of salt and saturated fats, and avoid all processed meat
Are there clinical trials available for chronic myeloid leukaemia that I can participate in?

Icon offers clinical trials across a wide range of cancer types and treatments. If you would like more information on participating in a clinical trial, please speak with your doctor who will be able to find a trial that might be right for you and your cancer. 

See current clinical trials delivered by Icon Cancer Centre. 


For a full list of references, click here.
  1. Cancer Council. (2018). Understanding Chronic Leukaemia: A guide for people with cancer,
  2. their families and friends. Retrieved 12 January 2022 from
  3. Leukaemia Foundation. (2020). Chronic myeloid leukaemia (CML). Retrieved 12 January 2022 from
  4. Cancer Council. (2020). Chronic myeloid leukaemia (CML). Retrieved 12 January 2022 from
  5. American Cancer Society. (2018). Chronic Myeloid Leukemia (CML). Retrieved 12 January 2022 from
  6. Macmillan Cancer Support. (2020). Chronic myeloid leukaemia (CML).. Retrieved 12 January 2022 from
  7. Cancer Australia. (2022). Leukaemia in Australia statistics. Retrieved 12 January 2022 from
  8. Australian Institute of Health and Welfare. (2021). Cancer data in Australia: Summary. Retrieved 12 January 2022 from
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