Myelodysplastic Syndromes

Myelodysplastic syndromes are a group of diseases caused by the inadequate production of healthy blood cells in the bone marrow. They are diseases of the blood and bone marrow.

Normally, the bone marrow makes blood stem cells (immature cells) that develop into mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. The lymphoid stem cell develops into a white blood cell. The myeloid stem cell develops into one of three types of mature blood cells:

  1. Red blood cells that carry oxygen and other materials to all tissues of the body.
  2. White blood cells that fight infection and disease.
  3. Platelets that help prevent bleeding by causing blood clots to form.

Continue reading below to learn more about myelodysplastic syndromes, including:

Myelodysplastic syndromes types

There are several types of myelodysplastic syndromes, all of which are characterized by too few of one or more types of healthy blood cells in the bone marrow or blood.

Myelodysplastic syndromes include the following diseases:

  • Refractory anemia
  • Refractory anemia with ringed sideroblasts
  • Refractory anemia with excess blasts
  • Refractory anemia with excess blasts in transformation
  • Refractory cytopenia with multilineage dysplasia
  • Myelodysplastic syndrome associated with an isolated del(5q) chromosome abnormality
  • Unclassifiable myelodysplastic syndrome

Myelodysplastic syndromes diagnosis

Tests that examine the blood and bone marrow are used to detect (find) and diagnose myelodysplastic syndromes. The following tests and procedures may be used.

  • Physical exam and history:  The doctor examines the body to check general signs of health and signs of disease, such as lumps or anything unusual. A history of the patient’s health habits and past illnesses and treatments are also taken.
  • Complete blood count (CBC) with differential: A sample of blood is drawn and checked for the following:
    • The number of red blood cells and platelets.
    • The number and type of white blood cells.
    • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
    • The portion of the blood sample made up of red blood cells.
  • Cytogenetic analysis: Cells in a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes.
  • Bone marrow aspiration and biopsy: The removal of bone marrow, blood and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood and bone under a microscope to look for abnormal cells.Myelodysplastic syndromes are diagnosed based on certain changes in the blood cells and bone marrow.
    • Refractory anemia: There are too few red blood cells in the blood, and the patient has anemia. The number of white blood cells and platelets is normal.
    • Refractory anemia with ringed sideroblasts: There are too few red blood cells in the blood, and the patient has anemia. The red blood cells have too much iron. The number of white blood cells and platelets is normal.
    • Refractory anemia with excess blasts: There are too few red blood cells in the blood, and the patient has anemia. Five percent to 19 percent of the cells in the bone marrow are blasts, and there are a normal number of blasts found in the blood. There also may be changes to the white blood cells and platelets. Refractory anemia with excess blasts may progress to acute myeloid leukemia.
    • Refractory anemia with excess blasts in transformation: There are too few red blood cells, white blood cells, and platelets in the blood, and the patient has anemia. Twenty percent to 30 percent of the cells in the bone marrow are blasts and more than 5 percent of the cells in the blood are blasts. Refractory anemia with excess blasts in transformation is sometimes called acute myeloid leukemia.
    • Refractory cytopenia with multilineage dysplasia: There are too few of at least two types of blood cells. Less than 5 percent of the cells in the bone marrow are blasts and less than 1 percent of the cells in the blood are blasts. If red blood cells are affected, they may have extra iron. Refractory cytopenia may progress to acute leukemia.
    • Myelodysplastic syndrome associated with an isolated del(5q) chromosome abnormality: There are too few red blood cells in the blood and the patient has anemia. Less than 5 percent of the cells in the bone marrow and blood are blasts. There is a specific change in the chromosome.
    • Unclassifiable myelodysplastic syndrome: There are too few of one type of blood cell in the blood. The number of blasts in the bone marrow and blood is normal, and the disease is not one of the other myelodysplastic syndromes.

Myelodysplastic syndromes staging

There is no staging system for myelodysplastic syndromes. Treatment is based on whether the disease developed after the patient was exposed to factors that cause myelodysplastic syndrome or the disease was previously treated. Myelodysplastic syndromes are grouped for treatment as follows:

  • De novo myelodysplastic syndromes develop without any known cause.
  • Secondary myelodysplastic syndromes develop after the patient was treated with chemotherapy or radiation therapy for other diseases or after being exposed to radiation or certain chemicals that are linked to the development of myelodysplastic syndromes. Secondary myelodysplastic syndromes may be harder to treat than de novo myelodysplastic syndromes.
  • Previously treated myelodysplastic syndromes.
  • The myelodysplastic syndrome has been treated but has not improved.

Myelodysplastic syndromes treatment options

De novo and secondary myelodysplastic syndromes

Treatment of de novo and secondary myelodysplastic syndromes may include the following:

  • Supportive care with transfusion therapy.
  • High-dose chemotherapy with stem cell transplant using stem cells from a donor.
  • Supportive care with growth factor therapy.
  • Chemotherapy with azacitidine, decitabine or other anticancer drugs.
  • Supportive care with drug therapy.
  • A clinical trial of a new anti-cancer drug.
  • A clinical trial of low-dose chemotherapy with stem cell transplant using stem cells from a donor.
  • A clinical trial of a combination of treatments.
  • A clinical trial of growth factor therapy.

Previously treated myelodysplastic syndromes

Treatment of previously treated myelodysplastic syndromes may include the following:

  • High-dose chemotherapy with stem cell transplant using stem cells from a donor.
  • Chemotherapy with azacitidine or decitabine.
  • Supportive care with transfusion therapy, growth factor therapy and/or drug therapy.
  • A clinical trial of low-dose chemotherapy with stem cell transplant using stem cells from a donor.
  • A clinical trial of new drug therapy.
  • A clinical trial of a combination of treatments.
  • A clinical trial of growth factor therapy.