# Myelodysplastic syndrome
What is it
Myelodysplastic syndrome (MDS) is a disease of the bone marrow in which blood cell formation is disrupted. Normally, the bone marrow continuously produces new red blood cells, white blood cells and platelets. In MDS, this process no longer works properly: the cells are not made correctly, do not function properly or break down prematurely.
This results in insufficient healthy blood cells in the blood. You then have too few oxygen carriers (red blood cells), too few immune cells (white blood cells) or too few clotting cells (platelets). The bone marrow contains many abnormal cells, but these do not help blood cells to function properly.
MDS is sometimes referred to as a "precursor to leukaemia" because some people with MDS can later develop acute leukaemia. However, this does not always happen; some people have MDS for years without it changing.
Causes
In most cases, it is unclear why someone develops MDS. It occurs because errors develop in the DNA of bone marrow cells that prevent these cells from growing properly and dividing correctly.
For some people, heredity plays a role: certain inherited genes can increase the risk of MDS. For most people, however, MDS is not hereditary.
Certain exposures can increase the risk:
- Previous chemotherapy or radiation for cancer
- Prolonged exposure to certain chemicals (such as benzene)
- Smoking
Age also plays a role: MDS becomes more common as you get older.
How the disease progresses
The severity of MDS can vary greatly from person to person. For some it progresses very slowly, for others somewhat faster.
Doctors classify MDS based on how severe it is and how likely it is to progress to acute leukaemia. They use, among other things, the number of abnormal cells in the bone marrow and the number of different chromosomal abnormalities.
**Low-risk MDS**: The bone marrow contains less than 5% abnormal cells. This often progresses slowly and can remain stable for years.
**Intermediate-risk MDS**: The percentage of abnormal cells is higher or certain chromosomal abnormalities are present. The risk of it progressing to leukaemia is greater.
**High-risk MDS**: The bone marrow contains 10-19% abnormal cells. The risk of transformation to acute leukaemia is considerable. Without treatment, this can happen within months to a few years.
Not everyone with MDS experiences the same disease course. Some patients have no problems for years, others notice the effects of blood cell deficiencies relatively quickly.
Symptoms by phase
**Early stage (low-risk MDS)**
In this stage, many people have no complaints, for example because the blood cell deficiency is still minor. Some people do already have:
- Fatigue and exercise intolerance (due to too few red blood cells)
- Regular bruising or minor bleeding (due to too few platelets)
- Getting sick more often or longer recovery from infections (due to too few white blood cells)
- Shortness of breath
- Dizziness
**Advanced phase**
As the blood cell deficiency increases:
- Severe fatigue and weakness
- Serious anaemia symptoms: headaches, concentration problems, pallor (paleness)
- Increased bleeding: nosebleeds or gum bleeds, haematomas (bruises)
- Recurrent infections, fever
- Breathing becomes more difficult, especially with exertion
**Upon transformation to leukaemia**
When MDS progresses to acute leukaemia, more serious symptoms can develop, such as:
- Severe fatigue
- Rapid breathing
- High fever
- Massive bleeding
- Swelling of the liver and spleen
It is important to know that symptoms are highly individual. Some people with many abnormalities feel well for a long time; others with fewer abnormalities have many complaints.
What it means for daily life
MDS can have a significant impact on daily functioning, but this varies enormously from person to person and depending on the phase of the disease.
**Fatigue**: This is often the most limiting symptom. Many people can no longer maintain their normal work or household routine. Taking it easy becomes necessary; effort must be spread throughout the day.
**Work**: Some people can continue their work, others must reduce their work pace, work from home, or stop working. This depends on the type of work, the severity of MDS, and how quickly it causes fatigue.
**Social and leisure activities**: Meetings with friends and family often have to be limited or better planned. Many people feel less inclined to be social.
**Medical treatment and check-ups**: Regular follow-up appointments (usually once a month to once every few months) are necessary. Sometimes transfusions are needed. This requires time, energy, and sometimes travel logistics.
**Infections**: The reduced number of immune cells means that infections can become serious more quickly. Being careful with hygiene and contact with sick people becomes important.
**Mental well-being**: The uncertainty about how things will progress and the risk of leukemia can be psychologically burdensome. Depression and anxiety are not uncommon and deserve attention.
**Relationships**: Partners and family also notice the changes. Communication about what is and isn't possible helps.
Many people with low-risk MDS can continue more or less normally for a long time, as long as it is well managed. With intermediate- or high-risk MDS, this is more difficult.
Outlook
The outlook for MDS is very dependent on various factors, especially the risk category, chromosomal abnormalities, the number of blast cells (immature cells), and how well the body responds to treatment.
**Low-risk MDS**: Many patients have a clearly longer survival time — sometimes more than ten years. However, for some it can change more quickly.
**Intermediate-risk MDS**: The duration varies greatly, from a few years to ten years or more. The chance of transformation to leukemia is present.
**High-risk MDS**: Without treatment, this can progress more quickly to acute leukemia (months to a few years). With effective treatment, this risk can be reduced, but the disease is serious.
In recent years, new treatment options have become available that have helped with certain forms of MDS. This has improved the outlook for some groups of patients.
**Important**: These figures apply to groups, not to individuals. Your own situation may be very different. Your doctor can assess what is realistic based on your specific abnormalities and response to treatment.
Also relevant: age, other health conditions, how well your body responds to treatment, and what chromosomal abnormalities you have.
Frequently asked questions
**Will I definitely get leukemia?**
No. Many patients with MDS do not develop leukemia. With low-risk MDS, this rarely happens. With high-risk MDS, the risk is greater, but not everyone develops leukemia even then. It depends on the specific abnormalities in the cells and how well it responds to treatment.
**Can MDS be cured?**
For some patients yes: a bone marrow or stem cell transplant can cure MDS, especially if caught in an early stage. This is a heavy treatment with risks, so the decision is made carefully. For others without a transplant, the disease can remain stable for a long time with supportive treatment. However, "cure" does not happen for everyone.
**What are blood transfusions and how often are they needed?**
If the number of red blood cells is too low, blood may be needed to replenish the oxygen carriers. Some people need transfusions very rarely, others regularly. This depends on how poorly the bone marrow is still functioning. Needing frequent transfusions can lead to complications in the long run (iron accumulation), so this is carefully monitored.
**How often do I need to go to the hospital?**
This varies greatly. Some patients with stable low-risk MDS have check-ups once every few months. With more active forms, this can be monthly or more. Treatment (for example, injections or tablets) can take place at home or in the hospital. Much depends on your specific situation and what treatment you receive.
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_This information never replaces a doctor's judgment. Always discuss your situation with your own healthcare provider._