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Diagnosis and treatment of CMML

Find out about how chronic myelomonocytic leukaemia (CMML) is diagnosed and the treatment you might have. You can also get tips about coping with this rare condition. 

Diagnosing CMML

Most people are diagnosed because doctors find abnormal monocytes during a blood test for something else. Your doctor may then arrange a number of tests for you, including:

  • blood tests to look at how many blood cells you have and whether they are normal
  • a bone marrow test

Your doctor may also do tests to look for anything unusual in the chromosomes of the CMML cells. Chromosomes contain the genetic material inside cells. These tests are called cytogenetics (pronounced sigh-toe gen-et-ics).

Treatment for CMML

The only way to get rid of CMML completely is to have a stem cell transplant but unfortunately this treatment is not suitable for everyone.

If you have no or few symptoms you might not need treatment at first. Instead you will have regular check ups including blood tests.

The type of treatment you need depends on:

  • the type of CMML you have

  • whether you have symptoms

  • your age

  • whether you have any other medical conditions

Supportive treatment

The aim of supportive treatment is not to cure the CMML but to reduce the number of blast cells, improve your symptoms and quality of life and delay a possible transformation to acute leukaemia.

Most people need supportive treatment at some point. The treatment you need depends on the type of symptoms you have. You might need a combination of treatments.

Blood and platelet transfusions

You might have blood transfusions if your red blood cells are low. And if your platelets are low you will have a drip of a clear fluid containing platelets.

Having a lot of blood transfusions can cause a build up of iron in your body. Red blood cells contain iron and your body stores this. But too much iron in your body can damage your heart and liver. To stop this, you might need to take medicines to get rid of the extra iron.

Growth factors

Growth factors are drugs that encourage your bone marrow to make more blood cells. We know from research that this can reduce the number of blood transfusions that people need.

Erythropoetin is a growth factor that increases the number of red blood cells. So you may have this if your red blood cell level is low. 

G-CSF is a growth factor that increases the number of white blood cells. So you may have this if your white blood cell levels are low.

You have both of these drugs as injections just under the skin (subcutaneously).


You might also need to take antibiotics to treat infections.


Chemotherapy uses cell killing (cytotoxic) drugs to destroy the abnormal cells.

The drugs work by disrupting the growth of cells and stopping them from dividing. You can have chemotherapy as a tablet, an injection just under your skin, or as an injection into a vein. You might have just one drug or a combination of drugs.

The type of chemotherapy you have depends on your type of CMML and your general health. If you have just been diagnosed your first chemotherapy is likely to be cytarabine, hydroxyurea or azacitidine.

If you are at high risk of developing AML you might have chemotherapy similar to that used to treat AML.

Donor stem cell transplant

In a donor stem cell transplant you have a very high dose of chemotherapy and you might also have total body irradiation (TBI). These treatments destroy the cells in your bone marrow. This treatment is very intensive and might get rid of the CMML completely but it is not suitable for everyone. 

After the high dose treatment you have stem cells from a donor through a drip into your bloodstream. The stem cells make their way into the bone marrow and start to make normal blood cells.

It takes from a few days to a few weeks for the numbers of blood cells to become normal. During this time you will need blood and platelet transfusions and are at a high risk of developing infections. Your doctor and nurses will give you antibiotics and anti viral drugs to try to prevent them.

You can only usually have it if you are younger and in good health, aside from your CMML.

Stem cell donors

To be able to have this treatment you need a stem cell donor. The donor is someone whose stem cells match yours. The most suitable donor is usually a close relative such as a brother or sister.


Doctors and researchers are looking into a number of other treatments for myeloproliferative or myelodysplastic disorders.

They are testing a new cancer drug treatment called decitabine. This is similar to azacitidine. They are also looking at different ways of using azacitidine.

You can find information about research trials looking at treatments for CMML on our clinical trials database. 

Coping with CMML

Coping with a rare condition can be difficult, both practically and emotionally. Being well informed about your condition and its treatment can help you to make decisions and cope with what happens.

The symptoms of CMML often mean that you may find it hard to do everyday things. Talk to your doctor or nurse about any symptoms you have. There may be supportive treatments that can help you. You might also feel better if you:

  • eat a healthy well balanced diet
  • do some exercise – after checking with your doctor
  • rest when you are tired

If you get tired easily, try to work out your priorities each day. Talk to your family and friends and ask for any help you need.

Last reviewed: 
20 Sep 2017
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