Myelodysplastic syndromes (MDS or myelodysplasia) are a group of diseases that develop in the bone marrow, the spongy tissue in bones. There is no cure, but treatment can slow the disease and ease symptoms.
What are myelodysplastic syndromes (MDS)?
Healthy bone marrow produces immature cells called stem cells, which can become other types of specialized cells. Stem cells can develop into three types of blood cells: red blood cells, white blood cells, and platelets. Myelodysplastic syndrome can involve one or all of these cells.
In myelodysplastic syndromes, stem cells never properly form into blood cells. These defective cells (called blasts) eventually die off. Without healthy blood cells, you can bleed more easily and develop anemia (not enough healthy red blood cells) and infections.
About one-third of people with MDS will develop acute myeloid leukemia at some point. The only potential cure for MDS is a stem cell transplant.
Causes and risk factors
Scientists suspect genetic changes (mutations) inside bone marrow may lead to myelodysplastic syndromes. These changes may occur due to exposure to radiation, tobacco smoke, or another outside substance. In other cases, genetic changes appear to be random.
Risk factors include:
- Age (rare under 60)
- Chemotherapy or radiation for cancer
- Exposure to chemicals, such as benzene, fertilizers, pesticides, and tobacco smoke
- Exposure to lead or mercury
- Genetic (inherited) disorders, including Fanconi anemia and Shwachman-Diamond syndrome
- Treatment for Hodgkin lymphoma, non-Hodgkin lymphoma, or acute lymphoblastic leukemia
You might not experience any signs of myelodysplastic syndromes at first. Many doctors find MDS when blood tests show low blood cell counts.
Symptoms may include:
- Easy bruising or bleeding (due to low platelet count)
- Frequent infections (due to low white blood cell count)
- Pale skin due to low red blood cell count (anemia)
- Shortness of breath
- Tiny red spots beneath the skin (petechiae)
Doctors have identified six types of myelodysplastic syndromes based on the affected blood cells. Identifying the type of MDS can help doctors determine the appropriate treatment. The types include:
- MDS with single lineage dysplasia: One abnormal blood cell type
- MDS with multilineage dysplasia: Two or three abnormal blood cell types
- MDS with ring sideroblasts: One or more abnormal blood cell types and red blood cells with rings of excess iron
- MDS with excess blasts: One or more abnormal blood cell type with blasts (immature cells) in the blood or bone marrow
- MDS with isolated del(5q) chromosome: Low red blood cells and mutation in DNA
- MDS, unclassifiable: Abnormal or reduced numbers of one or more blood cells, though blood cells might appear to look normal
To diagnose myelodysplastic syndromes, your doctor performs a physical exam and asks you about symptoms, your health history, and your family’s health history. Other tests may include:
- Blood tests: These tests show how advanced the cancer is and if you have any signs of infection. Blood tests can measure levels of white and red blood cells, the amount of inflammation in the body, and liver and kidney function. Doctors can also look for other causes of symptoms, such as low iron.
- Bone marrow biopsy and aspiration: During aspiration, doctors use a thin, hollow needle to remove a small amount of bone marrow (the spongy material inside bones). A biopsy involves removing a small amount of bone with bone marrow. These tests can determine the extent (stage) of cancer.
Watch and wait
Myelodysplastic syndromes grow slowly, so doctors often recommend a "watch and wait" approach, also known as watchful waiting or active monitoring. Evidence shows treating MDS in their early stages doesn’t offer any benefits.
While you'll have regular doctor visits and tests, you may not need treatment unless you develop symptoms or changes in your blood counts.
If you don’t have myelodysplastic syndromes symptoms, you may not need treatment right away. Your doctor may recommend treatment if you experience symptoms or the disease progresses.
Treatment options depend on the type of MDS and your overall health and age. They include:
- Blood transfusion: This therapy replaces damaged or dead blood cells with healthy cells. Transfusions can improve symptoms, such as anemia and bleeding.
- Medication: Certain drugs can increase your blood cell count and help blood cells mature. They can also treat infection or boost your immune system so you need fewer transfusions.
- Stem cell transplant: A stem cell transplant (also called a bone marrow transplant) may be an option if other treatments haven’t worked. The doctor extracts damaged stem cells (blood-forming cells in the bone marrow) and replaces them with healthy cells from a donor.
- Chemotherapy: These drugs destroy cancer cells. You receive chemotherapy drugs through an injection in the vein or in pill form.
- Clinical trials: Clinical trials available at some medical centers may give eligible patients access to promising treatments not widely available.
Other helpful organizations
The below organizations offer additional information and resources for MDS patients and their loved ones.