Myelodysplastic Syndrome: When the Bone Marrow Factory Gets a Bit Disorganised

A patient-friendly guide from Dr Ivo Andrejco, Consultant Haematologist

First things first: what on earth is MDS?

Myelodysplastic syndrome, or MDS, is a condition where the bone marrow does not make blood cells properly.

The bone marrow is the soft, spongy tissue inside some of your bones. Its job is to make blood cells every day. It is a bit like a very busy factory — usually reliable, usually quiet, and usually not asking for attention.

In MDS, the factory is still open, the lights are on, and the workers are trying their best — but the production line has become disorganised. Some blood cells are made poorly, some do not mature properly, and some never make it out of the factory at all.

So even though the bone marrow may be working hard, the blood counts in the bloodstream can be low.

Fig. 1 Bone marrow as a blood cell factory producing red cells, white cells and platelets.

What blood cells are affected?

Your bone marrow normally makes three main types of blood cells:

1. Red blood cells — the oxygen delivery vans

Red blood cells carry oxygen around the body. If they are low, this is called anaemia.

Anaemia can cause:

This is often the most common problem in MDS.

2. White blood cells — the infection security team

White blood cells help fight infection. In MDS, some patients have low white cells, especially a type called neutrophils.

This may increase the risk of infections, although not everyone with MDS gets frequent infections.

3. Platelets — the tiny repair crew

Platelets are small, but they take their job very seriously. When they are missing, the body notices.

Is MDS cancer?

This is one of the most common and most difficult questions.

The honest answer is: yes, MDS is considered a type of blood cancer, but it often behaves very differently from the cancers people commonly imagine.

Many people hear the word “cancer” and immediately picture something fast-growing, painful, or spreading through the body. MDS is different. It starts in the bone marrow and mainly causes problems by interfering with healthy blood production.

Some cases are slow and may be monitored for years. Others are more active and need treatment earlier.

So I often explain it like this:

MDS is not one single disease. It is a family of bone marrow disorders. Some are quiet and slow. Some are more serious. Our job is to work out which type you have and what it is likely to do.

Did I do something to cause this?

Usually, no.

Most people with MDS did nothing wrong. It is not caused by diet, stress, lack of exercise, wine, cheese, coffee, or that one time you ignored a multivitamin advertisement.

MDS usually happens because some of the stem cells in the bone marrow acquire genetic changes over time. These are changes inside the marrow cells themselves. They are usually not inherited from your parents and usually not passed onto your children.

MDS becomes more common as people get older, because bone marrow cells — like the rest of us — accumulate wear and tear over time.

In a smaller number of people, MDS can occur after previous chemotherapy or radiotherapy. This is called therapy-related MDS.

Why do I need a bone marrow biopsy?

Blood tests tell us what is happening in the bloodstream.

A bone marrow biopsy tells us what is happening in the factory.

It helps us answer important questions:

I appreciate that a bone marrow biopsy is not anyone’s idea of a relaxing morning out. Nobody wakes up thinking, “Wonderful, today feels like a bone marrow biopsy day.” But it is one of the most useful tests we have for understanding MDS properly.

Fig. 3 Blood test = looking at blood on the road, bone marrow biopsy = checking the factory where blood is made.

What are “blasts”?

Blasts are very immature blood cells.

A small number of blasts in the bone marrow can be normal, because the marrow is constantly making new cells. But in MDS, we pay close attention to the blast percentage.

Why?

Because a higher blast count can mean the MDS is more active and has a higher chance of turning into acute myeloid leukaemia, or AML.

Most people with MDS do not suddenly turn into AML overnight. This is usually something we monitor carefully over time.

Think of blasts as young apprentice cells. A few apprentices in the factory are normal. Too many apprentices, with not enough qualified workers, becomes a management problem.

Low-risk and high-risk MDS: what does that mean?

When haematologists say “risk”, we are usually talking about two things:

This is why we look at:

Not all MDS behaves the same way.

Some patients have MDS that is mainly a long-term anaemia problem. Others have MDS that needs more active treatment because the marrow disease is more aggressive.

The name “MDS” is therefore only the start of the conversation. The next question is: what sort of MDS is it?

What symptoms should I watch for?

Many symptoms come from low blood counts.

Please let your treating team know if you develop:

Some tiredness is expected with anaemia. But if you feel dramatically worse, please do not simply blame “getting older”, “being unfit”, or “the weather”. The weather is guilty of many things, but not everything.

How is MDS treated?

Treatment depends on the type of MDS, your blood counts, your symptoms, your overall health, and your goals.

There is no single treatment plan that suits everyone.

1. Monitoring

Some people do not need treatment straight away.

This can feel strange. Patients sometimes ask, “How can I have a blood cancer and you are just watching it?”

The reason is that early treatment is not always helpful for slower MDS. If the condition is stable and not causing symptoms, careful monitoring may be safer than rushing into treatment.

Monitoring usually means regular blood tests and clinic reviews.

This is not “doing nothing”. It is active surveillance — which is medical language for “watching carefully with a plan, not ignoring it while drinking coffee.”

Although, to be fair, coffee may still be involved.

2. Blood transfusions

If anaemia becomes significant, red blood cell transfusions can improve symptoms.

Transfusions do not cure MDS, but they can help people feel better by improving oxygen delivery.

Some people need transfusions only occasionally. Others need them regularly.

If transfusions are needed often over a long period, iron can build up in the body. In selected patients, we may discuss treatment to reduce iron overload.

3. Injections to stimulate red cell production

Some patients benefit from injections called erythropoiesis-stimulating agents, or ESAs.

These encourage the bone marrow to make more red blood cells.

They do not work for everyone, but in the right patient they can reduce transfusion needs and improve anaemia.

4. Medicines that target specific MDS types

Some MDS subtypes respond to specific treatments.

For example, some patients with a chromosome change called del(5q) may benefit from a tablet called lenalidomide.

Other medicines may be used depending on the genetic features of the MDS, blood counts, and risk category.

This is one reason modern MDS care increasingly relies on genetic testing. We are not just looking at the blood count; we are trying to understand the wiring problem inside the marrow cells.

5. Azacitidine or similar treatment

For higher-risk MDS, we may use treatment such as azacitidine.

Azacitidine is not traditional intensive chemotherapy. It works by changing the behaviour of abnormal marrow cells and can help improve blood counts, reduce transfusion needs, and delay progression in some patients.

It is usually given in cycles and requires regular monitoring.

6. Stem cell transplant

A stem cell transplant is currently the only treatment with the potential to cure MDS.

However, transplant is a major treatment and is not suitable for everyone. It depends on age, fitness, other medical conditions, donor availability, and the risk of the MDS.

For some patients, transplant is the right path. For others, the risks are too high and we focus on controlling the condition and maintaining quality of life.

In haematology, “can we do it?” is only half the question. The other half is “should we do it for this person?”

Can I live well with MDS?

Yes, many people can.

Living with MDS often means learning a new rhythm:

Patients often feel better once they understand what is being watched and why.

MDS can be emotionally difficult because it is not always visible from the outside. You may look well, but feel exhausted. This can be frustrating when family or friends say, “But you look fine.”

Looking fine is lovely. It is also not a blood test.

Practical tips

Keep a copy of your blood results

It helps to know your usual haemoglobin, neutrophil count, and platelet count.

You do not need to become a haematologist. One of us is enough. But understanding the trend can make the disease feel less mysterious.

Report fevers early

If your white cell count is low, infection can become serious more quickly. Ask your treating team what temperature should prompt urgent review.

Tell your doctor about bleeding

Do not ignore unusual bruising, nosebleeds, gum bleeding, or black stools.

Ask before starting supplements

Some supplements can affect bleeding risk, interact with medications, or simply make very expensive urine. Please check first.

Stay active, but be sensible

Exercise is helpful, but anaemia may limit what you can do. Listen to your body. This is not the time to prove a point to a treadmill.

Questions patients often ask

Will I need chemotherapy?

Not necessarily.

Many people with MDS do not need intensive chemotherapy. Some need monitoring, transfusions, injections, or lower-intensity treatments. Higher-risk MDS may need more active treatment.

Will it turn into leukaemia?

Some types of MDS can progress to acute myeloid leukaemia. The chance depends on the type of MDS, blast count, chromosome changes, gene mutations, and blood counts.

This is one of the reasons we do careful risk assessment.

Is it inherited?

Usually, no.

Most MDS is acquired over time and is not passed down in families.

Can diet fix it?

A healthy diet is good for general wellbeing, but it cannot usually correct MDS. MDS is a bone marrow stem cell disorder, not a lack of kale.

Kale is welcome. It is just not a haematology treatment plan.

Can I travel?

Often yes, depending on your blood counts, transfusion needs, infection risk, and treatment schedule. Please discuss travel plans early, especially international travel.

Should I avoid people with infections?

If your white cells are low, it is sensible to avoid close contact with people who are clearly unwell. You do not need to live in a bubble, but you should also not volunteer to babysit six children with influenza.

What I want my patients to remember

MDS is complicated, and it is completely normal if it takes more than one appointment to understand it.

The most important points are:

When patients are first diagnosed, they often feel overwhelmed. That is understandable. MDS comes with strange words, numbers, risk scores, and bone marrow reports that appear to have been written by someone allergic to plain English.

My job is to translate all of that into something useful.

You do not need to understand everything on day one. You only need to understand the next step, and we will build from there.

Final thought

If your bone marrow is a factory, MDS means the production line is not working properly. Our job is to inspect the factory, understand the fault, support the good workers, slow down the troublemakers, and keep you as well as possible.

And yes — unfortunately, the factory does not come with a user manual.

That is why you have a haematologist.