MYELODYSPLASTIC SYNDROME (MDS)

Myelodysplastic syndromes are a group of disorders caused by poorly formed or dysfunctional blood cells. Myelodysplastic syndrome (MDS) is a condition that affects the bone marrow and the blood cells it produces.

Your bone marrow makes different types of blood cells:

  • Red blood cells, which carry oxygen in your blood.
  • White blood cells of different types, which are important elements of your immune system.
  • Platelets, which help your blood to clot.

Myelodysplastic syndrome can turn into acute myeloid leukemia, a type of cancer.

Factors that may increase your risk of myelodysplastic syndromes include:

  • Older age. Most people with myelodysplastic syndromes are adults older than 60.
  • Treatment with chemotherapy or radiation. Your risk of myelodysplastic syndromes is increased if you received chemotherapy or radiation therapy, both of which are commonly used to treat cancer.
  • Exposure to certain chemicals. Chemicals linked to myelodysplastic syndromes include tobacco smoke, pesticides and industrial chemicals, such as benzene.
  • Exposure to heavy metals. Heavy metals linked to myelodysplastic syndromes include lead and mercury.

Types of Myelodysplastic Syndrome

  • Refractory cytopenia with unilineage dysplasia. In this type, one blood cell type is low in number. This type of blood cell appears abnormal under the microscope.
  • Refractory anemia with ringed sideroblasts. This type involves a low number of red blood cells. The existing red blood cells contain excess amounts of iron (ringed sideroblasts).
  • Refractory cytopenia with multilineage dysplasia. In this myelodysplastic syndrome, two of the three types of blood cells are abnormal, and less than 1 percent of the cells in the bloodstream are immature cells (blasts).
  • Refractory anemia with excess blasts — types 1 and 2. In both these syndromes, any of the three types of blood cells — red blood cells, white blood cells or platelets — may be low in number and appear abnormal under a microscope. Very immature blood cells (blasts) are found in the blood.
  • Myelodysplastic syndrome, unclassified. In this uncommon syndrome, there are reduced numbers of one of the three types of mature blood cells, and either the white blood cells or platelets look abnormal under a microscope.
  • Myelodysplastic syndrome associated with isolated del(5q) chromosome abnormality. People with this syndrome have low numbers of red blood cells, and the cells have a specific mutation in their DNA.

Symptoms of Myelodysplastic Syndrome

Often, myelodysplastic syndrome causes no symptoms early in the disease. But its effect on different types of blood cells can cause warning signs that include:

  • Fatigue. This is a common symptom caused by anemia, or lack of sufficient red blood cells.
  • Unusual bleeding
  • Bruises and tiny red marks under the skin
  • Paleness
  • Shortness of breath during physical activity

DIAGNOSIS

To diagnose myelodysplastic syndrome, your doctor may do the following:

  • Ask you about your symptoms and history of other health problems.
  • Do a physical exam to check for other possible causes of your symptoms.
  • Take a sample of blood to count the different types of cells and examine the blood cells under a microscope.
  • Take a sample of bone marrow for analysis. This requires inserting a special needle into the hip bone or breastbone to remove the sample.
  • Performing a genetic analysis of cells from the bone marrow.

 

RECOMMENDED MEDICATIONS

Treatment for myelodysplastic syndromes most often involves treatments to slow the progression of the disease and supportive care to help manage symptoms such as fatigue and to prevent bleeding and infections.

Blood transfusions

Blood transfusions can be used to replace red blood cells, white blood cells or platelets in people with myelodysplastic syndromes.

Medications

Medications used to increase the number of healthy blood cells your body produces include:

  • Medications that increase the number of blood cells your body makes. Called growth factors, these medications are artificial versions of substances found naturally in your bone marrow.
Some growth factors, such as epoetin alfa (Epogen) or darbepoetin alfa (Aranesp), can reduce the need for blood transfusions by increasing red blood cells. Others may help prevent infections by increasing white blood cells in people with certain myelodysplastic syndromes.
  • Medications that stimulate blood cells to mature, rather than remain immature. Medications such as azacitidine (Vidaza) and decitabine (Dacogen) may improve the quality of life of people with certain myelodysplastic syndromes and reduce the risk of acute myelogenous leukemia.
  • Medications that suppress your immune system. Medications used to suppress the immune system may be used in certain myelodysplastic syndromes.
  • Medication for people with a certain genetic abnormality. If your myelodysplastic syndrome is associated with a gene mutation called isolated del(5q), your doctor may recommend lenalidomide (Revlimid). Lenalidomide may reduce the need for blood transfusions in people with this gene mutation.

Bone marrow stem cell transplant

During a bone marrow stem cell transplant, your defective blood cells are damaged using chemotherapy drugs. Then the abnormal bone marrow stem cells are replaced with healthy, donated cells (allogeneic transplant).

Most bone marrow stem cell transplants used to treat myelodysplastic syndromes are reduced-intensity or “mini” transplants. This means the chemotherapy drugs used before the transplant are less powerful than those used in standard transplants and are likely to cause fewer side effects.

Still, even reduced-intensity transplants carry a significant risk of side effects. For this reason, few people with myelodysplastic syndromes are candidates for bone marrow stem cell transplant.

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