Myelodysplastic Syndrome (MDS)

MDS refers to a group of disorders that involve the primitive cells of the bone marrow and result in ineffective blood cell production causing low blood cells counts that are refractory to any current treatment. Such patients are at increased risk of developing acute leukemias. This illness originates in myeloid cells of the bone marrow. Normally, upon diagnosis, bone marrow is replaced by abnormal cells. Average age of patients at the time of diagnosis is 60-70 years. This disease does not respond to conventional treatment and the only method that may cure some patients is bone marrow transplant.

Cause:

The cause of this illness is unknown; however, exposure to radiation, certain pesticides, and some chemotherapy or non-chemotherapy drugs may induce MDS. Another factor is aging. This disease is much more common in elderly and it may be due to natural process of aging of be marrow.

Signs and symptoms

The most significant manifestations are due to failure of bone marrow to produce normal blood cells. Hence, most patients develop anemia, low white blood cells and low platelet counts. The most common symptoms include:

• Fatigue

• Weakness

• Paleness

• Bleeding

• Fever and infection

• Bone pain in arms, legs or back

Diagnosis

A complete blood count may give clues to this diagnosis. Some MDS cells may be seen and recognized under microscope. A bone marrow test should be performed. Since some patients may be ill at the time of diagnosis, other tests and procedures, blood tests, chest x-ray, etc., may be indicated. Cytogenetic study of the bone marrow is the most important test in establishing the diagnosis of MDS.

Classification

The nature of MDS and its prognosis varies from patient to patient. There are several pathological classifications for this group of diseases, The disease can be classified into 5 simple categories.

1. Refractory anemia

2. Refractory anemia with ring sideroblasts

3. Refractory anemia with increased blast cells

4. Refractory anemia in transformation into acute Leukemia

5. Chronic Myelomonocytic Leukemia

Entities in the lower end of the list are more difficult illnesses and have a worse prognosis with a shorter survival. Patients with Refractory anemia have a better prognosis and the illness may stay dormant for years, however, it will eventually progress into the more serious stages of this illness and even into Leukemia.

Treatment

This disease is one of the more difficult illnesses to treat. It is absolutely refractory to conventional treatments, including chemotherapy. The disease is more common elderly who cannot tolerate aggressive treatments. Those patients who are younger than 55 years of age should be considered for a bone marrow transplant, which can cure up to one third of patients.

Several drugs  have gained FDA approval for this disease:

Revlimid is an oral agent that is used in treatment of small subset of patients with MDS who have anemia and a particular chromosomal abnormality in their diseased bone marrow cells known as 5q deletion.

Vidaza is another drug that is given intravenously or as injection under the skin.

Dacogen is another drug that is given intravenously

Neupogen may be effective in patients with low white blood cell count. Procrit is minimally effective in treatment of the anemia in such patients. It is critical that this disease be managed by a well experienced Oncologist or Hematologist with a good insight into this illness.r