Tests and treatment for myelofibrosis

Myelofibrosis is a rare blood cancer. It causes scarring of the bone marrow which makes it more difficult to produce blood cells.

To find out if you have myelofibrosis your doctor will do several tests. They will also examine you and ask you questions about your general health and family history.


The first test to diagnose myelofibrosis is usually a blood test called a full blood count. This is to check the number of:

  • red blood cells
  • white blood cells Open a glossary item
  • platelets Open a glossary item

Most people with myelofibrosis have a low number of red blood cells. This is called anaemia. Red blood cells contain haemoglobin, and so your haemoglobin will also be low. Haemoglobin carries oxygen around the body. So, if you are anaemic, you may feel tired or breathless.

Many people with myelofibrosis might have a higher or lower than normal number of white blood cells and platelets at diagnosis. These usually drop as the condition progresses.

You might also have blood tests to look for gene Open a glossary item changes. For example, in the JAK2 or CALR and MPL genes.

Doctors are learning more about genetic changes all the time. You might have tests for other gene changes.

Other tests

Other tests you might have to help diagnose myelofibrosis include:

  • a bone marrow aspirate or biopsy

  • an ultrasound scan of your tummy (abdomen) - to check the size of your spleen and liver

  • an MRI scan

  • a CT scan

Your doctor might arrange for you to have other blood tests or scans if they need more information to confirm a diagnosis. They will let you know more about these tests if you need them.

Your risk group and outlook

There are particular factors that doctors use to work out whether your myelofibrosis is low, medium or high risk to your health. This is called the International Prognostic Scoring System (IPSS).

The Dynamic International Prognostic Scoring System (DIPSS) helps doctors work out your risk at any point during your myelofibrosis treatment.

These systems help your healthcare team decide on the best treatment for you.

There are 4 risk groups:

  • low risk

  • intermediate 1

  • intermediate 2

  • high risk

At diagnosis, your risk group depends on:

  • your white blood cell levels - a high one is higher risk

  • your haemoglobin - less than 100g/L is a higher risk

  • the number of blasts (immature blood cells) in your blood

  • your symptoms - for example if you have weight loss or sweats

  • your age - if you are over 65 years you are higher risk

Newer scores are sometimes available using particular DNA Open a glossary item changes inside the myelofibrosis cells. It may help to talk to your specialist about which scoring system they are using.

In general, low risk myelofibrosis can be kept under control for several years in some people. High risk myelofibrosis can be more difficult to treat.

The predicted outlook of myelofibrosis depends on many factors. It is best to discuss your outlook with your own specialist. They have access to all your test results and how they have changed over time.

Treatment for myelofibrosis

Your treatment depends on a number of factors including:

  • your blood cell levels at diagnosis

  • your symptoms

  • the number of immature cells you have in your blood

  • your risk group


Your doctor can decide on the best treatment for you by looking at the scoring system and finding your risk group. They will also take into account your general health and any other medical conditions. 

You might not need to start treatment if you don’t have symptoms. Instead, you have regular check ups, including blood tests to check your blood count.

Treatments might include one or more of the following:

Blood transfusions increase the number of red blood cells. This helps to control tiredness, breathlessness and weakness.

You take aspirin as a tablet. It can help to reduce the risk of your blood clotting if you are at risk of developing them. Blood clots can cause heart attacks or strokes. Aspirin helps to prevent platelets from sticking together. This means that there is a lower risk of them forming a clot. 

When red blood cells are broken down by the body, they produce uric acid. If you have too much uric acid in your blood, it can collect in the joints and cause painful swelling, called gout. Allopurinol lowers the amount of uric acid in the blood and so helps to reduce the symptoms of gout.

You have allopurinol as a tablet.

Folic acid is a vitamin that helps the body make red blood cells. You may have this if you have anaemia. 

JAK2 inhibitors work by slowing or stopping the growth of cancer cells. They stop the JAK2 gene from signalling to stem cells to make blood cells.


Ruxolitinib is used to treat an enlarged spleen and other symptoms. It's ususlly for people who have intermediate or high risk myelofibrosis. 


Some people might have fedratinib to treat an enlarged spleen or other symptoms. This is for people with myelofibrosis who have already had treatment with ruxolitinib.


You might have momelotinib to treat an enlarged spleen or symptoms of anaemia. You might have it if you have not had a JAK inhibitor or have previously had ruxolitinib. It's usually for people with intermediate 2 or high risk myelofibrosis. 

Chemotherapy uses cytotoxic Open a glossary item drugs to destroy the immature cells. The drugs work by disrupting the growth of cells and stopping them from dividing. They can help to reduce enlargement of the spleen and liver.

Chemotherapy is not suitable for everyone because one of the side effects is the lowering of the number of blood cells. 

Doctors might recommend that you have one of the following:

  • hydroxycarbamide

  • busulfan

  • melphalan

You have some of these drugs as tablets, or as a drip into your bloodstream (intravenous).

Pegylated interferon is a type of immunotherapy. It helps to reduce the rate at which blood cells are made.

You might have pegylated interferon if you have tried other treatments for myelofibrosis and they are not working for you. You are more likely to have this treatment if you have low risk myelofibrosis. You usually have it as an injection just under the skin (subcutaneously).

Erythropoietin is a growth factor Open a glossary item which encourages your body to make more red blood cells.

A donor stem cell transplant Open a glossary item is usually only suitable for people who:

  • are younger

  • are in reasonably good health, apart from your myelofibrosis

  • have a suitable donor

  • are in the higher risk group

This is an intensive treatment and it has many risks. This is why it’s not suitable for everyone. Your doctor can explain if this is a suitable treatment for you.

Your doctor may suggest you take danazol. It’s from a group of drugs called androgens. Androgens are hormones made by the adrenal glands Open a glossary item. Doctors sometimes use artificial androgens to help to control anaemia. You take them as a tablet.

Androgens have side effects including an increase in body hair, swelling around the legs and feet and retention of fluid. 

Radiotherapy is the use of radiation, usually x-rays, to kill cells. Your doctor might suggest you have radiotherapy if your spleen is enlarged and you are unable to have surgery.

This helps reduce the size of your spleen, but it usually only controls symptoms for a few months.

You might have an operation to remove your spleen (splenectomy) if it is enlarged and other treatments haven't been able to reduce the size. 

The operation has risks for someone with myelofibrosis. These include infection, bleeding and development of blood clots. So, it's not a suitable treatment for everyone.

Treatment for myelofibrosis if you are pregnant

You can’t have some treatments for myelofibrosis if you are pregnant. Your doctor will discuss this with you. They will explain the treatments you can have and the possible side effects.

Clinical trials

Your doctor might ask you to take part in a clinical trial if one is available for your situation. Doctors and researchers do trials to make existing treatments better and develop new treatments.

Healthy lifestyle

Your healthcare team might discuss ways to maintain a healthy lifestyle and help with stopping smoking if you need it.

We have information on healthy diet and lifestyle on our causes of cancer and reducing your risk pages.

Support and coping

We have information on support organisations that can help you cope with the diagnosis and treatment of myelofibrosis.

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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
05 Feb 2024
Next review due: 
05 Feb 2027

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