What is chronic myeloid leukaemia (CML)?

Chronic myeloid leukaemia (also called CML or CML leukemia) is a cancer of the blood cells.

About 750 people in the UK are diagnosed with CML each year. CML can affect people at any age, but it is more common as people get older. It usually develops very slowly. For many people, CML can be well controlled, and it will not shorten their life.

We have separate information about other types of leukaemia.

How chronic myeloid leukaemia develops

Blood cells are made in the bone marrow. The bone marrow is the spongy material found inside our bones. The bone marrow usually makes billions of new blood cells every day to replace old and worn-out blood cells.

All blood cells are made from blood stem cells. These are blood cells at the earliest stage of their development (called blast cells). There are two types of blood stem cell:

  • lymphoid stem cells – which make a type of white blood cell called lymphocytes
  • myeloid stem cells – which make the other white blood cells such as neutrophils, red blood cells and platelets.

 

MACD190 Blood cells labelled
Image: How blood cells divide

 

CML develops when some white blood cells start behaving abnormally.

Symptoms of chronic myeloid leukaemia (CML)

CML develops slowly and many people do not have symptoms in the early stages. Sometimes CML is found by chance when you have a blood test before an operation, or as part of a routine health check.

In the early stages of CML, any symptoms are usually mild and develop slowly. They can be confused with the symptoms of more common illnesses, such as flu.

We have more information about general symptoms of leukaemia.

Causes and risk factors of chronic myeloid leukaemia (CML)

It is not clear why people get CML. It is not linked to smoking, diet, exposure to chemicals or infections. It also does not run in families. Like other cancers, CML is not infectious and cannot be passed on to other people.

There are some factors that might increase the risk of developing CML.

  • Age
  • Sex
  • Radiation exposure

How chronic myeloid leukaemia (CML) is diagnosed

If your GP thinks you may have CML, they will refer you to a haematologist for further tests. A haematologist is a doctor who specialises in diagnosing and treating blood problems.

The haematologist will ask you about any illnesses or health problems you have had. They will examine you to check if your spleen is enlarged.

Tests for CML may include:

  • Blood tests
  • Bone marrow test
  • Cytogenetic and molecular tests
  • Ultrasound scan

Phases of chronic myeloid leukaemia (CML)

Doctors know the phase of CML from:

  • the number of immature blood cells (blast cells) in your the blood and bone marrow
  • the symptoms you have.

Most people are diagnosed when CML is in the chronic phase.

CML usually develops slowly. There are three phases of CML.

  • Chronic phase
  • Accelerated phase
  • Blast phase
  • Relapse

Treatment of chronic myeloid leukaemia (CML)

A team of specialists will meet to discuss the best possible treatment for you. This is called a multidisciplinary team (MDT).

Your cancer doctor or specialist nurse will explain the different treatments and their side effects. They will also talk to you about certain things to think about when making treatment decisions.

The aim of treatment is to put CML into remission (where there are no signs of leukaemia cells). Treatments used can include the following:

  • Tyrosine kinase inhibitors (TKIs)
  • Chemotherapy
  • Stem cell transplant
  • Interferon alpha
  • Leukapheresis
  • Clinical trials

We have more information about treatment for CML.

Fertility and chronic myeloid leukaemia (CML) treatment

Some cancer treatments can affect fertility or harm a developing baby. Because of this you may be advised to use contraception to prevent a pregnancy. If you want to have children or think you may in the future, talk to your doctor about this as soon as possible. They can talk to you about the possible options for planning your treatment.

We have more information about fertility for men and fertility for women.

Living with chronic myeloid leukaemia (CML)

Follow-up and monitoring CML

If you have treatment with a TKI, you will be monitored by your healthcare team every 1 to 2 weeks.

At these check-ups, your doctor will:

  • ask about your general health
  • ask about any new symptoms or side effects of treatment
  • do blood tests to check the numbers of blood cells (FBC) and leukaemia cells (PCR test).

Sometimes they may take a bone marrow sample. Your doctor can tell you how often you might need this.

These test results help your doctors know how well the treatment is working to control the leukaemia. They will also check for any side effects. They can make any changes if needed.

As time goes on, you will not need to see your doctors as often. Eventually, you may only need a check-up every 3 to 6 months.

If you have another type of treatment, your doctor or nurse will tell you how often you will have appointments.

Well-being

Most people with CML live a normal lifespan. To help you stay as well as possible, you may want to make changes to your lifestyle. Even if you had a healthy lifestyle before your diagnosis, you may want to make the most of your health.

A healthy lifestyle does not have to be difficult or expensive. It is about making small changes to the way you live. This will improve your health and sense of well-being. It will also lower your risk of getting other illnesses and some other cancers.

Understanding more about CML and its treatment can also help you cope. This means you can discuss treatment, tests and check-ups with your doctors and nurses. It also means you can be involved in making decisions. This can make you feel more confident and more in control. Here are some things to consider:

  • Get involved in your healthcare
  • Self-help and support groups
  • Online support

Getting support

Everyone has their own way of dealing with illness and the different emotions they experience. You may find it helpful to talk things over with family and friends or your doctor or nurse. 

The organisations below offer information and support:

  • Anthony Nolan
    Anthony Nolan is the UK’s largest stem cell and bone marrow register.
  • Leukaemia CARE
    Leukaemia CARE provides care and support to patients, their families and carers whose lives have been affected by leukaemia, lymphoma or a related blood disorder.
  • Blood Cancer UK
    Blood Cancer UK is a blood cancer research charity that provides information and support on any type of blood cancer.

Macmillan is also here to support you. If you would like to talk, you can:

About our information

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We want everyone affected by cancer to feel our information is written for them.

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Date reviewed

Reviewed: 01 December 2020
|
Next review: 01 December 2023

This content is currently being reviewed. New information will be coming soon.

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