Chronic myeloid leukaemia

Leukaemia is cancer of the white blood cells. Chronic leukaemia means the condition progresses slowly over many years.

Chronic leukaemia is classified according to the type of white blood cells that are affected by cancer. There are two main types:

  • lymphocytes – mostly used to fight viral infections
  • myeloid cells – which perform a number of different functions, such as fighting bacterial infections, defending the body against parasites and preventing the spread of tissue damage

These pages focus on chronic myeloid leukaemia, which is a cancer of the myeloid cells. The following other types of leukaemia are covered elsewhere:

What happens in chronic leukaemia

Your bone marrow produces stem cells. These are unique cells because they have the ability to develop into three important types of blood cell:

  • red blood cells – which carry oxygen around the body
  • white blood cells – which help fight infection
  • platelets – which help stop bleeding

In leukaemia, a genetic mutation in the the stem cells causes a huge over-production of white blood cells and corresponding drop in red blood cells and platelets.

It's this lack of red blood cells which causes symptoms of anaemia, such as tiredness, and the lack of platelets that increases the risk of excessive bleeding.

Warning signs of chronic myeloid leukaemia

In its early stages, chronic myeloid leukaemia usually causes no noticeable symptoms. As the condition develops, symptoms include:

  • tiredness 
  • weight loss 
  • night sweats
  • a feeling of bloating
  • bruising 
  • bone pain 

Read more about the symptoms of chronic myeloid leukaemia

How common is chronic myeloid leukaemia?

Chronic myeloid leukaemia is quite a rare type of cancer. Around 8,600 people are diagnosed with leukaemia every year in the UK. In 2011, around 680 people in the UK were diagnosed with chronic myeloid leukaemia.

Chronic myeloid leukaemia can affect people of any age, but it is more common in people aged 40-60. There is no evidence that it runs in families.


The outlook for chronic myeloid leukaemia depends to a large extent on how well a person responds to medication.

Most patients (60-65%) do well on imatinib tablets, which are taken every day for life.

For those who don't do well on imatinib, more than half respond to one of the alternative drugs. Nilotinib is recommended by the National Institute for Health and Care Excellence (NICE) for patients with chronic myeloid leukaemia who are not responding to, or can't tolerate imantinib.

Those who fail these drugs or cannot tolerate them may be offered a bone marrow transplant, if this is a suitable treatment.

Read more about the treatment of chronic myeloid leukaemia.

If the condition is diagnosed early (the chronic phase), the outlook is excellent, with almost 90% of people living at least five years after diagnosis.

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