Myelodysplasia is also known as myelodysplastic syndrome (MDS). MDS is a type of blood cancer that affects the bone marrow. It causes low levels of one or more types of blood cells in the blood.
MDS is more common in people aged over 70, but it can happen at any age. You are not born with MDS and it cannot be passed on in families.
Sometimes MDS can develop into acute myeloid leukaemia.
There are different types of MDS. Some types develop slowly. Others develop quickly and have a greater risk of changing into leukaemia. Your specialist can explain more about the type of MDS you have.
To understand MDS and its treatment, it can help to know more about your blood and bone marrow.
Causes of MDS
In most cases, the cause of MDS is unknown. This is called primary MDS.
A small number of people develop MDS after treatment with chemotherapy or radiotherapy. This is called secondary or treatment-related MDS (t-MDS).
There are different types of MDS. These are based on:
- which blood cells (red cells, white cells or platelets) have become abnormal
- how many immature blood cells (blasts) you have
- if there is a chromosome change called del 5q in the blood cells.
Your haematologist can tell you the name of the type of MDS you have. They will explain how this may affect your treatment.
The names for different types of MDS can be confusing. Do not worry if you find this section difficult to follow. You can ask your haematologist or specialist nurse to explain the type of MDS you have. This can include:
MDS with single lineage dysplasia (MDS-SLD)
Only one type of blood cell has become abnormal.
MDS with multilineage dysplasia (MDS-MLD)
Two or more types of blood cell have become abnormal.
MDS with ring sideroblasts (MDS-RS)
Some of the cells in the bone marrow have a ring of iron in them. These cells are called ring sideroblasts.
This type can be further divided, based on if one or more types of cell are abnormal:
- MDS-RS-SLD (MDS with ring sideroblasts and single lineage dysplasia)
- MDS-RS-MLD (MDS with ring sideroblasts and multilineage lineage dysplasia).
MDS with excess blasts (MDS-EB)
There are a higher than normal number of blast cells in the blood and bone marrow. This can be further divided into the following, depending on the numbers of blasts cells:
MDS associated with isolated del (5q)
The cells in the bone marrow have a chromosome change called isolated del (5q).
MDS unclassified (MDS-U)
This type includes any type of MDS which does not fit into any of the above categories. If you have one of these, your haematology team can explain more about it.
The main symptoms of MDS are caused by low levels of healthy blood cells. Symptoms include:
- feeling weak and tired because of a lack of red blood cells (anaemia)
- becoming breathless when you are active because of a lack of red blood cells (anaemia)
- having repeated infections because of a low number of white blood cells
- bruising or bleeding because of a low number of platelets.
Some people are diagnosed with MDS after a blood test for another reason and before they have any symptoms.
You will see a doctor who specialises in blood disorders called a haematologist. MDS is diagnosed with blood tests and a bone marrow test.
Full blood count (FBC)
Bone marrow samples
Genetic tests on bone marrow cells
These tests help your doctor to be certain that your diagnosis is MDS. The results can also tell them how it may behave in the future.
A doctor examines the chromosomes inside the bone marrow cells taken during your bone marrow test. This is called cytogenetic testing. Chromosomes are groups of genes. They contain the instructions for the cell and control how it behaves. Changes in the chromosomes can affect how MDS behaves over time.
Waiting for test results can be a difficult time. It may help to talk to your family, friends or specialist nurse.
MDS is divided into different risk groups. These give an idea about:
- how quickly or slowly MDS may develop
- the risk of it developing into leukaemia.
Knowing your risk group can help you and your doctor to think about the best treatment options for you.
The MDS risk groups are based on:
- your blood count
- how many immature blood cells (blasts) there are in your bone marrow
- the results of cytogenetic tests.
Doctors often use a system called the revised International Prognostic Scoring System (IPSS-R). It divides MDS into 5 risk groups:
- very low-risk
- very high-risk.
Your haematologist may use other risk groups to describe your MDS.
Your doctor will talk with you about treatment options. Treatments may be used to help with symptoms of MDS, or to help to control it. Less commonly, the aim of treatment may be to try to cure MDS.
The best treatment for you will depend on:
- the risk group you are in
- the type of MDS you have
- your general health
- your own preferences and what is important to you.
If you have very low-risk, low-risk or intermediate-risk MDS without symptoms, you may not need treatment straight away. Instead, you will have regular check-ups and your blood counts will be monitored. This is sometimes called active monitoring or watch and wait.
You and your doctors will talk about your treatment options and their possible risks and benefits.
Reducing your risk of infection
Treatment to control MDS
Different treatments can be used to help to control MDS.
Drugs called growth factors stimulate the bone marrow. They may help to increase the number of healthy red and white blood cells in your blood.
A growth factor called erythropoietin may be used to increase the number of red blood cells in your blood and reduce the number of blood transfusions you need.
A drug called G-CSF may be given to increase the number of white blood cells in your blood.
Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. It can also be given to help control MDS. The type of chemotherapy you have will depend on your general health and how MDS is affecting you. The aim is to get your bone marrow working better.
Chemotherapy can be given as an outpatient or during a short stay in hospital.
You usually have chemotherapy as an injection into a vein (intravenously). It is sometimes given as an injection under the skin (subcutaneously). You may have a single drug or two or more drugs together (combination chemotherapy).
Azacitidine (Vidaza®) is a chemotherapy drug for people with higher risk MDS who are not able to have, or do not want, more intensive treatment. It can help the bone marrow to work better. You have azacitidine as an injection under the skin. The side effects include discomfort at the injection site, sickness and tiredness. It also reduces your blood count for a short time.
High doses of chemotherapy may be offered to people with higher risk MDS. This treatment is also used treat acute leukaemia. You will need to stay in hospital for several weeks to have this.
If this treatment works well, you may have a donor stem cell transplant afterwards.
Donor stem cell transplant (allogeneic transplant)
A small number of people with higher-risk MDS, whose general health is good, may be able to have a donor stem cell transplant. This treatment can sometimes cure MDS. But it can also cause serious side effects, so it is not suitable for most people. You and your doctor will need to consider the possible advantages against the risks of having the treatment.
Drugs that suppress the immune system can sometimes improve the blood count in people with MDS. These drugs are called immunosuppressants. They include anti-thymocyte globulins (ATGs) and ciclosporin.
Doctors are investigating different treatments that may be used to help to control MDS.
You may be invited to join a clinical trial looking at new ways of treating MDS. You can talk about this with your haematologist or nurse.
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.
You will need regular check-ups and blood tests. If you are worried or notice any new symptoms between appointments, tell your haematologist or specialist nurse or as soon as possible.
Macmillan can offer emotional, practical and financial help and support.
The organisations below also offer information and support:
MDS UK Patient Support Group
Blood Cancer UK