MDS

What is MDS?

Myelo = bone marrow
Dysplastic = strangely or abnormally-shaped

Myelodysplastic Syndromes (MDS) are a group of malignant blood disorders in which the bone marrow makes the cells badly, causing low blood counts and cells that don’t work properly.

Cells that can be affected:

  • Red cells (erythrocytes) – which carry oxygen to organs and tissues in the body.
  • White cells – which collectively fight against infection.
  • Platelets (thrombocytes) – which prevent bruising and bleeding.

Classification of MDS

There are six broad types of MDS included in the current World Health Organisation (WHO) classification (2008):

  • Refractory cytopenia with unilineage dysplasia (RCUD)
  • Refractory anemia with ring sideroblasts (RARS)
  • Refractory cytopenia with multilineage dysplasia (RCMD)
  • Refractory anemia with excess blasts (RAEB)
  • Myelodysplastic syndrome unclassified (MDS-U
  • MDS associated with del(5q), including the 5q- syndrome

Epidemiology of MDS

The overall incidence of MDS is slightly higher in males than in females (1.5 to 2:1). The incidence of MDS increases with age, with a median age at diagnosis of about 70 years. MDS is rare in children; childhood cases are more frequently associated with monosomy of chromosome 7.

Symptoms of MDS

A person with MDS may suffer from the following:

  • Chronic tiredness and weakness (Anemia). This is due to the low levels of hemoglobin in the red blood cells, which carries oxygen to the body.
  • Spontaneous bleeding and bruising. This is due to low platelet numbers, which prevent bleeding and bruising.
  • Recurrent infections. This is due to low and/or poorly functioning white blood cells meaning that the body is unable to fight off infection normally.

Diagnosis of MDS

Diagnosis of MDS is based on the:

  • Full blood count
    1. Reduced erythrocytes and thrombocytes.
    2. Reduced hemoglobin.
    3. Other cell types may be reduced or increased.
  • The appearance of the bone marrow
    1. There may be the formation of blasts. The higher the levels of blasts the worse the prognosis. >30% blasts in bone marrow suggest transformation to AML.
  • Any chromosome changes found.
    1. Some genetic mutations may have better prognosis than others.

Blood and bone marrow samples are analyzed using specialist tests, which include morphological analysis using microscope imagining, flow cytometry to look at cell shape and size, and cytogenetics to look for genetic mutations.

Management of MDS

Treatment choices should take into account the following:

  • What type of MDS does the patient have?
  • How aggressive is the MDS?
  • Are any symptoms particularly troubling?
  • Is there a chance for curative therapy?
  • How does the patient want to be treated?
  • Are there clinical trials available?

Treatment options can range from the ’supportive’ to ‘intensive’.

Red cell transfusion Symptomatic anemia
Platelet transfusion Chronic low platelets-bleeding & bruising
Planned surgical operation
Granulocyte-colony stimulating factor Infections associated with a low white count
Antibiotic Infections
Iron chelation therapy Patients with low-risk disease with more than 25 units of red cell transfusion

 

Erythropoietin

  • Given as an injection
  • May improve anemia in patients with MDS
  • May reduce the need for red cell transfusion
  • Seems to work best when given with white cell growth factor G-CSF.

Lenalidomide

  • Oral medication
  • Considered for 5q syndrome
  • Works by altering the immune system
  • Reduces the need for transfusion in over 60% of patients.

Azacitidine (Vidaza)

  • Given as an injection (subcutaneous or intravenous)
  • Generally well tolerated
  • Work by changing the behavior of cancer cells at the DNA level.
  • Slows progression of the disease

Intensive chemotherapy

This treatment is the same as that used to treat acute myeloid leukemia (AML) and aims to kill a significant proportion of the abnormal cells in the bone marrow to allow the bone marrow to work normally again (remission). Patients generally need to stay in hospital for four to six weeks for each course due to high chance of side-effects which may include the following:

  • nausea
  • vomiting
  • diarrhea
  • loss of appetite
  • sore mouth and mouth ulcers (mucositis)
  • tiredness
  • skin rashes
  • hair loss
  • infertility – which may be temporary or permanent

Bone-marrow transplant

A stem cell transplant (or bone marrow transplant) should be considered when there is ‘curative’ therapy is thought to be appropriate. Healthy bone marrow or stem cells are taken from another person whose tissue DNA is identical or almost identical to yours, so the donor is compatible with you. Before transplantation can take place, the person receiving the transplant will need to have intensive high-dose chemotherapy and possibly radiotherapy to destroy the cells in their bone marrow. The donated stem cells are given through a tube into a blood vessel, in a similar way to chemotherapy medication. The treatment has many side effects and it is important that the decision is thought of carefully.

There are a number of things to bear in mind if opting for this procedure:

  • Suitable for ‘high-risk’ MDS with disease under control.
  • Complicated process with many risks involved.
  • Donor match – a donor needs to be identified which can take a while.
  • Age is important – younger and fitter suggests a great chance of success.
  • Cost – expensive procedure if not provided by the country.
  • Availability – not all countries support this treatment.

For more information on MDS please visit the MDS Alliance website: https://www.mds-alliance.org