Myelodysplastic Syndrome

Myelodysplasia is the term used to describe a group of disorders that is characterized by the deficiency of the bone marrow to produce enough normal red blood cells, white blood cells, and platelets. A decreased number of red blood cells in the body causes the hemoglobin to drop, which decreases the amount of oxygen that is carried by the cells. When there are too few white blood cells in the body, the patient is more vulnerable to infection. Platelets allow blood to clot, thus when there are too few platelets, a patient may bruise or bleed easily. In myelodysplasia patients the bone marrow also produces an excess of immature blood cells called blasts, which can collect and damage the bone marrow even further.

Doctors from around the world met at a conference 1982 and developed the French-American-British (FAB) system to classify types of myelodysplastic syndrome. The FAB system made the following classifications:

1. Refractory anemia (RA) - this is characterized by the bone marrow's failure to produce enough healthy red blood cells.
2. Refractory anemia with ring sideroblasts (RAS) - this is very similar to regular refractory anemia, however there are additional abnormalities present in the red blood cells.
3. Refractory anemia with excess blasts (RAEB) - in this type of anemia an increase in the production of immature blast cells accompanies the abnormalities with the red blood cells.
4. Refractory anemia with excess blasts in transformation (RAEB-t) - this type is very similar to RAEB but with an even high number of blasts cells.
5. Chronic myelomonocytic leukemia (CMML) - this type is characterized by the presence of too many white blood cells in the bone marrow.

For many patients there is no obvious cause for their diagnosis of myelodysplasia; however, there are known factors that increase a person's risk for developing myelodysplasia. People who have had radiation therapy or been exposed to industrial solvents, such as benzene, are at a greater risk for developing myelodysplasia. Benzene is a known human carcinogen, meaning it has the potential to cause cancer. Benzene is often linked to leukemia and other blood related diseases, such as myelodysplastic syndrome.

Patients who are suffering from myelodysplastic syndrome often experience symptoms that are very common to a variety of blood disorders and other medical problems, which makes the disease difficult to recognize. In fact, about 20 percent of myelodysplasia patients do not recognize any symptoms but are eventually diagnosed through a routine blood test. If symptoms do occur, they may include bruising, nausea, shortness of breath, fatigue, pale skin, fever, and/or dizziness.

The first step toward a diagnosis of myelodysplastic syndrome is to have a blood test. A doctor then looks at the blood sample to see if any abnormalities are present and to determine the number of red cells, white cells, and platelets that exist in the blood. To get a firm diagnosis, the doctor typically has to examine a small sample of the patient's bone marrow.

A variety of treatment options are available to patients who have been diagnosed with myelodysplastic syndrome. When deciding which treatment plan is right for a patient, it is necessary to take into consideration the patient's age, overall health, and desires regarding treatment. Some of the most common forms of treatment are listed below.

• Transfusions - are the most common form of treatment for myelodysplasia patients. Transfusions are often given in combination with antibiotics and other medications in an effort to make the patient feel as comfortable as possible. This is helpful because most myelodysplasia patients are over 60 years of age. Transfusions are useful in making a patient feel better, but it is not generally possible to experience long-term results solely through transfusion treatments.
• Growth factors - are given to patients to help the body produce white blood cells, which cannot be supplied through transfusions because of their short lifespan (typically one day or less). Unfortunately, growth factors are not an effective form of treatment for all patients.
• Chemotherapy - is administered to kill the abnormal cells in the bone marrow and blood, which will hopefully allow healthier cells to grow in their place. Chemotherapy is accompanied by a number of side effects because it also kills healthy cells in the body. Side effects from chemotherapy can include nausea, hair loss, lack of energy, and a weakened immune system.
• Transplants - are generally considered the best option available to achieve long-term results. Bone marrow or stem cell transplants are the typical types of transplants recommended to treat myelodysplasia patients. Transplants are often accompanied by chemotherapy or radiation therapy to kill as many unhealthy cells as possible so that the transplanted bone marrow or stem cells will be able to produce healthy cells in their place.

For more detailed information see the National Cancer Institute's statements on this disease.