Myelodysplastic syndrome (MDS)

Myelodysplastic syndrome is a disease of the bone marrow, the tissue inside the bones where blood cells are made. A stem cell picks up a fault and starts turning out defective work: the cells mature badly and die before they ever reach the bloodstream. The marrow may even be crowded while the blood stays empty. That accounts for the whole picture: too few red cells, too few platelets, too few of the white cells that fight infection. MDS is counted among the blood cancers because it has a single source, an altered clone of cells, and in some people it eventually turns into acute myeloid leukaemia.

Three shortages behind the symptoms

MDS has no symptoms of its own: what a person notices is not the disease but the lack of the cells the marrow has stopped delivering. That gives three sets of signs, mixed in different proportions in each patient.

• Too few red cells: constant tiredness that a weekend does not fix, breathlessness on level ground, palpitations, ringing in the ears, pallor of the skin and especially of the inner eyelids and lips; on darker skin the pallor is harder to see.
• Too few platelets: bruises from the lightest knock, gums that bleed with brushing, frequent nosebleeds, heavy periods, and tiny red dots on the legs and feet that do not fade when a clear glass is pressed on them.
• Too few neutrophils: colds that drag on for weeks, repeated sore throats and chest infections, cuts that are slow to heal, and a temperature with no obvious cause.

All of this creeps on over months, which is why it is so easily put down to age or overwork. In some people the illness turns up by chance, in a blood test taken before an operation or for something else entirely.

Why the marrow goes wrong

In most patients no cause can be named. As the years pass, stem cells accumulate faults in their genes, and MDS is largely the disease of that accumulation: the great majority of cases appear over the age of sixty or seventy, and slightly more often in men.

The known circumstances that raise the risk are few: previous chemotherapy or radiotherapy for another cancer, long occupational contact with benzene and other organic solvents, smoking, and some rare inherited syndromes in which the marrow is fragile from childhood. If close relatives have had MDS or leukaemia, tell the haematologist: occasionally there is a familial gene fault behind it, and then relatives are looked at too, especially if one of them is being considered as a donor.

MDS is not catching, and only in rare cases is it inherited. Diet, temperament and past upheavals do not bring it on.

How the diagnosis is reached

It all starts with a full blood count, but it does not end there: a low haemoglobin is a finding, not a diagnosis.

• A blood film under the microscope: the doctor sees that the cells are not merely scarce but abnormal in shape and maturity.
• Tests that rule out reversible causes: iron and ferritin, vitamin B12 and folate, thyroid, kidney and liver function, signs of chronic inflammation. A good share of anaemia in older people is explained this way and is simple to put right.
• A bone marrow biopsy is the test that makes the diagnosis. A needle takes a small core of bone and a drop of marrow, usually from the hip bone, under local anaesthetic and sometimes with light sedation. It takes about a quarter of an hour, and without it a diagnosis of MDS is not regarded as established.
• Genetic testing of the marrow cells: chromosome changes and mutations define the type of disease, the outlook and the choice of treatment.

The proportion of immature cells, the blasts, is measured separately. While they stay below a fifth, the illness is called MDS; once they cross that line it is called acute myeloid leukaemia. The answer does not come in a day: the genetic work takes weeks, and that wait does not mean bad news.

Why the risk group decides everything

MDS is not one disease but a dozen variants with different fates. So that everyone is not treated alike, doctors work out a risk group, from very low to very high. The calculation takes in the proportion of blasts, the set of genetic faults and how far the blood counts have fallen.

At low risk the illness may sit almost unchanged for years, and the main task is to keep the person well without subjecting them to unnecessary treatment. At high risk the threat of turning into acute leukaemia comes to the front, and treatment is then started actively and without gaps. The same haemoglobin figure will be handled differently in two people from different groups, and that is calculation rather than carelessness.

What the treatment does

Only a marrow transplant can cure MDS, and it suits a minority. For everyone else the aim is different: to keep the blood at working levels and push back the change into leukaemia.

• Watching and waiting. At low risk and with tolerable counts no treatment is given at all: regular blood tests and reviews, with action when it is needed. This is not a refusal to help but a recognised approach.
• Supportive treatment is the mainstay for most: red cell transfusion for anaemia, platelet transfusion for dangerous bleeding, and prompt antibiotics for infection.
• Drugs that push the marrow: erythropoietin helps some people at low risk and stretches out the gaps between transfusions; growth factors for white cells are sometimes added.
• Hypomethylating agents, azacitidine above all, are the main treatment at high risk. They are given in cycles; rather than flattening the marrow they nudge the abnormal cells towards working normally, and the first benefit takes several cycles to show.
• Lenalidomide works in one particular chromosome fault, the loss of part of chromosome 5, and can free a person from transfusions for a long time.
• Drugs that damp down the immune system suit an uncommon variant in which the marrow is left empty.
• A stem cell transplant from a donor is the only chance of cure. It is hard going and carries real risk, so it is discussed with those who could withstand it, and decided in good time rather than once the disease has moved on.

After many transfusions iron builds up in the body and starts to damage the heart and the liver. Ferritin is tracked and, if needed, drugs that remove iron are prescribed. For the same reason iron tablets should never be started on your own initiative: the anaemia of MDS is not caused by a lack of it.

When waiting is not an option

With low white cells an infection moves fast and its usual signs are blunted. A temperature above 38 degrees in someone with MDS is a reason to contact the haematologist at once or to go to hospital, rather than take something for the fever and wait for morning. In that situation antibiotics are started within hours.

Call an ambulance (in most European countries, 112) if there is:

• shivering with a high temperature, confusion, sudden collapse or a drop in blood pressure;
• bleeding that will not stop: from the nose for more than twenty minutes, heavily from the gums, blood in the urine, black tarry stools, vomiting blood;
• a sudden severe headache or disturbance of vision or speech while the platelets are low;
• severe breathlessness at rest, chest pain, or a blackout.

See a doctor the same day for a new rash of pinpoint bleeds, for breathlessness and weakness building over days, for any infection with a temperature below 38 degrees, and if mouth ulcers appear that get in the way of eating and drinking.

Life between appointments

The main rule is simple: guard against infection without turning life into a lockdown. Flu vaccination every year, pneumococcal and covid vaccination as your doctor advises; live vaccines are not given while the marrow is suppressed. See the dentist regularly and always mention the diagnosis, since a tooth extraction with low platelets is planned together with the haematologist.

Painkillers need care. Ibuprofen and other anti-inflammatory drugs, and aspirin as well, raise the risk of bleeding and are not suitable when platelets are low; paracetamol is usually safer, though its dose is worth agreeing too. No new medicine or supplement should be started without telling the haematologist.

The tiredness of anaemia cannot be beaten by willpower, but it does respond to gentle activity: short walks are tolerated better than complete rest. It is worth eating well, washing vegetables thoroughly and avoiding raw meat and fish while the white cells are deeply low, protecting the skin from cuts and shaving with an electric razor.

If the disease has advanced and cure is no longer possible, treatment does not stop — it changes its aim. The palliative care team deals not with the last days but with control of symptoms: it relieves breathlessness, pain and distress, and supports the family too. Bringing them in early is sensible; late is not.

Online consultation

An online appointment is useful when you have the result in hand but not the explanation. The doctor goes through the blood count, explains what the low figures mean, says which tests are worth having before you see the haematologist so that no weeks are lost, and helps tell a straightforward anaemia from a situation that calls for a marrow biopsy.

Once the diagnosis is made, the doctor turns the report from medical language into plain words, explains what the risk group means, helps with the side effects of treatment and points out which symptoms must not wait for the next scheduled visit. Bring all the blood tests of recent months, because it is the trend and not a single number that matters, along with the letters and the list of medicines. An online consultation does not replace a face-to-face haematology assessment or a bone marrow biopsy. Fever and bleeding need urgent care, not a message.

This material is for information only and does not replace medical advice.