(See also Overview of Leukemia Overview of Leukemia Leukemias are cancers of white blood cells or of cells that develop into white blood cells. White blood cells develop from stem cells in the bone marrow. Sometimes the development goes awry... read more .)
Symptoms depend on which type of cells is affected but may include tiredness, weakness, and paleness, or fever and infections, or bleeding and bruising.
Blood tests and examination of a bone marrow sample are needed for diagnosis.
Treatment with azacytidine and decitabine may help relieve symptoms and lower the likelihood that acute leukemia will develop.
Stem cell transplantation can cure the disease.
In myelodysplastic syndromes, a line of identical cells (clone) develops and occupies the bone marrow. These abnormal cells do not grow, mature, or function normally. The cells also interfere with normal bone marrow function, resulting in deficits of
Red blood cells Red Blood Cells The main components of blood include Plasma Red blood cells White blood cells Platelets read more
(which carry oxygen in the bloodstream), causing anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more White blood cells White Blood Cells The main components of blood include Plasma Red blood cells White blood cells Platelets read more
(which help defend the body against infection), causing infectionsPlatelets Platelets The main components of blood include Plasma Red blood cells White blood cells Platelets read more
(small cell-like particles that help in the clotting process), causing bleeding and bruising
In some people, red blood cell production is predominantly affected.
Myelodysplastic syndromes occur most often in people older than 50 years, particularly those older than 65 years. Men are more likely than women to be affected.
The cause is usually not known. However, in some people, exposure of bone marrow to radiation therapy or certain types of chemotherapy drugs may play a role.
Symptoms of MDS
Symptoms may develop very slowly. Fatigue, weakness, and other symptoms of anemia are common. Fever due to infections may develop if the number of white blood cells decreases. Easy bruising and abnormal bleeding can result if the number of platelets drops (thrombocytopenia Overview of Thrombocytopenia Thrombocytopenia is a low number of platelets (thrombocytes) in the blood, which increases the risk of bleeding. Thrombocytopenia occurs when the bone marrow makes too few platelets or when... read more 
).
Diagnosis of MDS
Blood tests
Bone marrow examination
Molecular testing
A myelodysplastic syndrome may be suspected when people have unexplained persistent anemia, but diagnosis requires bone marrow evaluation Bone Marrow Examination Red blood cells, most white blood cells, and platelets are produced in the bone marrow, the soft fatty tissue inside bone cavities. Sometimes a sample of bone marrow must be examined to determine... read more .
At some centers, people are tested to determine which gene or chromosome abnormalities are causing myelodysplastic syndrome (sometimes called molecular testing). Experimental treatments are now available that target some of these specific abnormalities.
Prognosis for MDS
Myelodysplastic syndromes are thought to be a type of preleukemia that can progress gradually over a period of several months to years. In 10 to 30% of people, a myelodysplastic syndrome transforms into acute myeloid leukemia Acute Myeloid Leukemia (AML) Acute myeloid leukemia is a life-threatening disease in which the cells that normally develop into the types of white blood cells called neutrophils, basophils, eosinophils, and monocytes become... read more 
(AML).
Treatment of MDS
Chemotherapy
Sometimes stem cell transplantation
The drugs azacitidine and decitabine help relieve symptoms and lower the likelihood that acute leukemia will develop. Azacitidine may also improve survival. Stem cell transplantation Stem Cell Transplantation Stem cell transplantation is the removal of stem cells (undifferentiated cells) from a healthy person and their injection into someone who has a serious blood disorder. (See also Overview of... read more is the only curative treatment and is usually done in young people.
If transformation to AML occurs, chemotherapy, such as that given for AML Treatment Acute myeloid leukemia is a life-threatening disease in which the cells that normally develop into the types of white blood cells called neutrophils, basophils, eosinophils, and monocytes become... read more may be helpful, but this type of AML is unlikely to be curable with chemotherapy alone.
Treatment of complications of myelodysplastic syndrome
People with myelodysplastic syndromes often need transfusions of red blood cells Overview of Blood Transfusion A blood transfusion is the transfer of blood or a blood component from one healthy person (a donor) to a sick person (a recipient). Transfusions are given to increase the blood's ability to... read more 
. A drug called lenalidomide, which attacks cells functioning with a specific chromosome abnormality, decreases the need for blood transfusions. Platelets are transfused only if people have uncontrolled bleeding or if surgery is needed and the number of platelets is low.
People who have very low numbers of neutrophils—the white blood cells that fight infection—may benefit from periodic injections of a special type of protein called granulocyte colony-stimulating factor. People may also benefit from the proteins erythropoietin, which may help in the production of red blood cells, and thrombopoietin, which stimulates the development of platelets.
More Information
The following are English-language resources that may be useful. Please note that the MANUAL is not responsible for the content of these resources.
Leukemia & Lymphoma Society: Myelodysplastic Syndromes: General information on many aspects of myelodysplastic syndromes, including diagnosis, treatment options, and research findings
MDS Foundation: What is MDS?: Provides information on causes of myelodysplastic syndrome, statistics on numbers of people affected, and treatment options
Drugs Mentioned In This Article
| Generic Name | Select Brand Names |
|---|---|
decitabine |
Dacogen |
azacitidine |
ONUREG, Vidaza |
lenalidomide |
Revlimid |
