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General Information About Myelodysplastic Syndromes

Myelodysplastic syndromes are a group of diseases in which the bone marrow does not make enough healthy blood cells.

Myelodysplastic syndromes are diseases of the blood and bone marrow. Normally, the bone marrow produces stem cells (immature cells) that develop into mature blood cells. There are 3 types of mature blood cells:

• Red blood cells that carry oxygen and other materials to all tissues of the body.


• White blood cells that fight infection and disease.


• Platelets that help prevent bleeding by causing blood clots to form.

In myelodysplastic syndromes, the stem cells do not mature into healthy red blood cells, white blood cells, or platelets. The immature blood cells, called blasts, do not function normally and either die in the bone marrow or soon after they enter the blood. This leaves less room for healthy white blood cells, red blood cells, and platelets to develop in the bone marrow. When there are fewer blood cells, infection, anemia, or easy bleeding may occur.

There are several types of myelodysplastic syndromes.

Myelodysplastic syndromes have 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.

Refer to the following PDQ summaries for information about other blood cell diseases:

• Myelodysplastic/Myeloproliferative Disease Treatment


• Chronic Myeloproliferative Disorders Treatment

Age and past treatment with chemotherapy or radiation therapy affect the risk of developing a myelodysplastic syndrome.

Risk factors include the following:

• Being older than 60 years.


• Past treatment with chemotherapy or radiation therapy.


• Being exposed to certain chemicals, including tobacco smoke, pesticides, and solvents such as benzene.

Possible signs of myelodysplastic syndrome include feeling tired and shortness of breath.

Myelodysplastic syndromes often do not cause early symptoms and are sometimes found during a routine blood test. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

• Shortness of breath.


• Weakness or feeling tired.


• Having skin that is paler than usual.


• Easy bruising or bleeding.


• Petechiae (flat, pinpoint spots under the skin caused by bleeding).


• Fever or frequent infections.

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: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.


• Complete blood count (CBC) with differential: A procedure in which 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.
  


• Peripheral blood smear: A procedure in which a sample of blood is checked for changes in the number, type, shape, and size of blood cells and for too much iron in the red blood cells.


• Cytogenetic analysis: A test in which 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 a small piece of bone and bone marrow by inserting a needle into the hipbone or breastbone. A pathologist views both the bone and bone marrow samples 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% 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. Refer to the PDQ Adult Acute Myeloid Leukemia Treatment summary for more information.


• 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% of the cells in the bone marrow are blasts and more than 5% 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% of the cells in the bone marrow are blasts and less than 1% 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% 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.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) depends on the following:

• Whether the myelodysplastic syndrome occurred after chemotherapy or radiation therapy for another disease.


• The number of blast cells in the bone marrow.


• Whether one or more types of blood cells are affected.


• Certain changes in the chromosomes.

Treatment options depend on the following:

• Whether the myelodysplastic syndrome occurred after chemotherapy or radiation therapy for another disease.


• Whether the myelodysplastic syndrome has progressed after being treated.


• The age and general health of the patient.

Stages of Myelodysplastic Syndromes

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 whether the disease was previously treated. Myelodysplastic syndromes are grouped for treatment as follows:

De novo myelodysplastic syndromes

De novo myelodysplastic syndromes develop without any known cause.

Secondary myelodysplastic syndromes

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 gotten better.

Treatment Option Overview

There are different types of treatment for patients with myelodysplastic syndromes.

Different types of treatments are available for patients with myelodysplastic syndromes. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with a myelodysplastic syndrome. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate treatment is a decision that ideally involves the patient, family, and health care team.

The usual goal of treatment for myelodysplastic syndromes is to prevent symptoms and related problems.

At this time, there is no treatment that will cure myelodysplastic syndrome or stop it from becoming acute leukemia. The usual treatment is supportive care, which helps many patients manage the disease. The main goal of treatment is to prevent symptoms and problems caused by low blood cell counts, such as fatigue and infections. If the disease is severe or gets worse quickly, a more aggressive treatment may be given, such as chemotherapy to kill the blast cells. Side effects of chemotherapy may cause serious health problems and many patients do better with standard supportive care.

Three types of standard treatment are used:
Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Supportive care

Supportive care is given to lessen the problems caused by the disease or its treatment. Supportive care may include the following:

• Transfusion therapy

   Transfusion therapy (blood transfusion) is a method of giving red blood cells, white blood cells, or platelets to replace blood cells destroyed by disease or treatment. Patients who receive frequent red blood cell transfusions may have their tissues and organs damaged from the build up of extra iron. Iron chelation therapy is a treatment that uses drugs that attach to the extra iron. The drug and the iron are removed from the body in the urine.

   Platelet transfusions are usually given when the patient is bleeding or is having a procedure that may cause bleeding.



• Drug therapy

   Erythropoietin may be given to increase the number of red blood cells and lessen the effects of anemia. Sometimes granulocyte colony-stimulating factor (G-CSF) is given with erythropoietin to help the treatment work better.

   Anticancer drugs may also be used.

   Antibiotics may be given to fight infections.

Chemotherapy with stem cell transplant

Stem cell transplant is a method of giving chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of a donor and are frozen for storage. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.

Treatment Options for Myelodysplastic Syndromes

De Novo Myelodysplastic Syndromes

Treatment of de novo myelodysplastic syndromes may include the following:

• Supportive care.


• Chemotherapy.


• Stem cell transplant using stem cells from a donor.


• A clinical trial of a new anticancer drug.


• A clinical trial of low-dose chemotherapy with stem cell transplant using stem cells from a donor.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Secondary Myelodysplastic Syndromes

Treatment of secondary myelodysplastic syndromes may include the following:

• Supportive care.


• Chemotherapy.


• Stem cell transplant using stem cells from a donor.


• A clinical trial of a new anticancer drug.


• A clinical trial of low-dose chemotherapy with stem cell transplant using stem cells from a donor.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

Previously Treated Myelodysplastic Syndromes

Treatment of previously treated myelodysplastic syndromes may include the following:

• Supportive care.


• A clinical trial of a new treatment, such as stem cell transplant.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.

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