What Are Myelodysplastic Syndromes?  

Myelodysplastic Syndromes (MDS) are a group of hematologic neoplasms; which means that there is an abnormal mass of tissue or abnormal cell growth in the blood, components of the blood, or blood-forming organs.

MDS Risk Factors

MDS is commonly found in the elderly above 65 years old, most commonly in patients over 80 years old. It predominantly affects caucasian males. 

Many risk factors are thought to contribute to developing MDS. The main risk factors for developing MDS are:

• History of radiation or toxins (like benzene) exposure
• History of chemotherapy, especially with alkylating agents (cyclophosphamide) and Topoisomerase II inhibitors (doxorubicin) in the last 10 years
• Family history of MDS
• De novo mutations
• Idiopathic etiology (which means there is nothing specific from a clinical standpoint that could explain how the disease developed) 

How is MDS Diagnosed?

MDS is diagnosed after reviewing the findings from the peripheral blood and bone marrow tests and determining they meet the accepted criteria for diagnosis. 

When an abnormal cell population grows in a blood forming organ like bone marrow, it affects the production of other blood cells necessary for the body to function correctly. For initial evaluation, MDS may be suspected if one or more blood cell type counts come back low, which is why blood work containing a complete blood count is very helpful to assess the levels of each cell type present in the blood. 

When other potential causes of the lower-than-normal number of blood cells are discarded, and the physician suspects MDS, they may order a blood smear to see how the cells look under a microscope. A diagnostic evaluation should also include a bone marrow biopsy and genetic testing of the bone marrow cells. 

A diagnosis of MDS requires a histopathologic evaluation, and has to meet the following diagnostic criteria:

• One or more peripheral blood cytopenias (anemia, neutropenia and/or thrombocytopenia) that cannot be explained by other causes
• Blasts which account for less than 20% of nucleated cells in the bone marrow and/or peripheral blood
• Evidence of dysplasia in greater than 10% of cell lines (red cell precursors, granulocytes or megakaryocytes.)

Cytogenetic analysis by FISH is also typically done to identify chromosomal abnormalities as this can influence both prognosis and treatment.

Once the risk stratification and assessment of MDS for a patient is completed by their doctor, selecting a course of therapy can be challenging as MDS has proven to be refractory to cytotoxic chemotherapy. Fortunately, research has given us advances in treatment leading to a more promising prognosis and future in MDS progression and quality of life.