Myelodysplastic syndrome

What are Myelodysplastic Syndromes?

The myelodysplastic syndromes are a group of disease in which the production of blood cells by the bone marrow is disrupted.

Only a minority of patients with MDS develop acute myeloid leukaemia.

The bone marrow in MDS is typically hyperactive and yet the number of blood cells in the circulation is reduced. This is because most of the cells being produced in the bone marrow are defective and are destroyed before they leave the bone marrow.

Cause

Although most patients have no obvious cause for their disease certain chemicals, chemotherapy drugs and ionising radiation may lead to MDS. MDS may therefore develop after treatment for lymphoma, myeloma, ovarian cancer, testicular cancer or breast cancer. The median age at diagnosis is between 65 and 75 years.

Treatment

MDS is often difficult to treat.

Treatment is often planned according to the IPSS score which is determined by:

• The proportion of leukaemia (blast) cells in the bone marrow
• The number of blood cell types which are reduced
• Cytogenetics (the chromosome changes that can be seen in MDS)

The only potentially curative option is a donor stem cell transplant in younger fitter patients.

IPSS low

Neither intensive chemotherapy nor stem cell transplantation is recommended for this group of patients as they have a comparatively long median survival with supportive care only.

Supportive care may be in the form of regular red blood cell or platelet transfusions to treat anaemia or low platelet counts respectively. Patients who develop iron overload as a result of numerous blood transfusions may require iron chelation therapy.

Recombinant human erythropoietin may be of benefit in some patients with MDS to specifically stimulate red blood cell production and reduce the need for red blood cell transfusions.

IPSS Intermediate/high

Patients under 65 years and fit for transplant should be assessed for fitness and eligibility for a donor stem cell transplant as soon as possible after diagnosis.

Patients who are not eligible for a transplant should be considered for 5-azacytidine chemotherapy which has been shown to reduce blood transfusion requirements and slow the progression to acute myeloid leukaemia leading to an improvement in overall survival for these patients.