United Kingdom
Change

Support and offers for individual members and customers

Health Information

Chronic myeloid leukaemia (CML)

Published by Bupa's health information team, March 2009.

This factsheet is for people who have chronic myeloid leukaemia (CML), or who would like information about it.

Chronic leukaemia is a cancer of the blood that develops slowly. There are two main types of chronic leukaemia, depending on the type of cells affected: chronic lymphocytic leukaemia (CLL) or chronic myeloid leukaemia (CML).

For information about leukaemia in general, see Related topics.

About CML
Symptoms of CML
Causes of CML
Diagnosis of CML
Treatment of CML
Living with CML
Further information
Questions and answers
Related topics
Sources

About CML

According to Leukaemia Research, about 750 people are diagnosed with CML each year. It's most common in people aged between 40 and 60 but it can occur at any age. It's very rare in children.

The term leukaemia refers to a group of cancers of the blood cells. In leukaemia, white blood cells become abnormal and divide and grow in an uncontrolled way. Leukaemia is described as acute (growing rapidly) or chronic (growing slowly). Chronic leukaemia is divided into two main types - chronic lymphocytic leukaemia (CLL) or chronic myeloid leukaemia (CML). This factsheet focuses on chronic myeloid leukaemia (CML).

The bone marrow produces two main types of white blood cells - lymphoid and myeloid - which work together to fight off infections. In CML, there are abnormal stem cells in your bone marrow, which mature into slightly abnormal myeloid cells (sometimes called granulocytes) in the bloodstream. You may also hear this type of leukaemia referred to as chronic granulocytic leukaemia (CGL).

Symptoms of CML

Initial symptoms of CML are usually due to the excessive proliferation of white cells in the bone marrow, blood and spleen. Some people with CML won't have any symptoms at first, and many of the symptoms are vague and seem like those of flu.

Symptoms of CML may include:

feeling generally tired and weak
looking pale
bleeding or bruising more easily
losing weight unintentionally
headaches and vision problems
pain or discomfort in the tummy (abdominal pain) due to an enlarged spleen
itching
aching bones and joints, due to the pressure of cell build-up
sweating at night
in men, erections which won't go down and are painful

These symptoms aren't always due to CML but if you have them, you should visit your GP.

Causes of CML

Some of the factors for developing CML include the following.

Age - the risk of CML increases with age. It's most common in people between 40 and 60.
Gender - men are slightly more likely than women to develop CML.
Radiation exposure - you are slightly more likely to develop leukaemia if you have had radiotherapy for another cancer.
Chemical exposure - exposure to cancer-causing substances (carcinogens) such as benzene over a long period of time increases the risk of developing CML.
Genes - an abnormal chromosome called the Philadelphia chromosome is the diagnostic finding in CML. This is not passed on in families but occurs by chance in the blood cells. This chromosome contains a gene called BCR-ABL which produces a protein that is a key factor in the development of CML. This is identified by testing the leukaemia cells.

Diagnosis of CML

Diagnosis, investigation, treatment and follow-up for people with chronic myeloid leukaemia usually take place at specialist centres in hospitals.

People with suspected leukaemia are referred to a haematologist, a doctor who specialises in the treatment of blood disorders. Tests carried out to investigate CML include:

a blood test
a physical examination to check whether the spleen is enlarged
removal of a sample of bone marrow for analysis under a microscope - this is done under local anaesthetic and the bone marrow sample is taken from your hipbone (pelvis) or breastbone (sternum)
genetic analysis of the abnormal blood cells - to identify the Philadelphia chromosome and BCR-ABL gene
tissue typing - if your doctor feels that you may need a bone marrow transplant

These tests are important because they help determine which treatment is best for you.

Staging CML

There are stages of CML which have been outlined as follows.

The chronic phase - less than five in every 100 cells in the bone marrow are immature blood cells, known as blasts. About nine in 10 people with CML are in this phase when they go to their doctor.
The accelerated phase - between five and 30 in every 100 cells in the bone marrow are immature blast cells. Symptoms become more severe, including losing weight, bruising and having abdominal pain or discomfort. This is caused by your spleen (which is to the left of your stomach, under your ribs) which may be enlarged.
The blast phase - more than 30 in every 100 of the cells in your bone marrow are immature blast cells, and these will have spread to other organs. If you are in the blast phase you often feel very ill.

Treatment of CML

Tyrosine kinase inhibitors

Imatinib is an example of this group of medicines which have become the first-line treatment of CML and are taken by mouth with relatively few side-effects in most people. They specifically target the BCR-ABL gene and can get rid of the Philadelphia chromosome from the blood and bone marrow to potentially cure the disease.

Chemotherapy

Medicines, such as hydroxycarbamide which is taken by mouth and has very few side-effects, can fully control chronic phase CML but don't destroy the Philadelphia chromosome. Therefore the disease can still progress to the accelerated or blast phases. Your doctor will advise you about the treatment you will receive. Your doctor will give you advice about the side-effects of your specific chemotherapy medicines, and may prescribe other medicines to help reduce any side-effects such as feeling or being sick, digestive problems, such as diarrhoea, and swelling.

Monoclonal antibodies

Certain cancers may also respond to treatment with monoclonal antibodies. Antibodies are molecules that are made naturally by our immune systems. Their role is to seek out foreign cells and kill them off. Monoclonal antibodies (eg interferon alpha) can be made in a laboratory and be designed to seek out particular cells. These can destroy CML cells containing the Philadelphia chromosome. Side-effects include headache, fever and depression.

High-dose treatment with bone marrow or peripheral stem cell transplant

If you have CML, you may be advised to have high doses of chemotherapy treatment and a bone marrow or stem cell transplant. A bone marrow transplant is where healthy bone marrow from a donor is fed into your bloodstream through a drip. A peripheral stem cell transplant involves transplanting stem cells, rather than bone marrow cells. Stem cells can be collected (harvested) from another person and fed into your bloodstream through a drip.

This treatment carries certain risks; it's now usually used to treat you if you haven't responded well to tyrosine kinase inhibitors, or have a bad reaction to them.

Living with CML

Being diagnosed with leukaemia can be distressing for you and your family. Specialist cancer doctors and nurses are experts in providing the care and support you need. There may be support groups so you can meet people who may have similar experiences to you. Ask your doctor for advice.

Further information

Cancer Research UK
0808 800 4040
www.cancerhelp.org.uk
Leukaemia CARE
0800 169 6680
www.leukaemiacare.org.uk
Leukaemia Research
020 7405 0101
www.lrf.org.uk
Macmillan Cancer Support
0808 800 1234
www.macmillan.org.uk