Myelodysplastic syndromes

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at October 30, 2016
StartDiseasesMyelodysplastic syndromes

Myelodysplastic syndromes or MDS are considered a group of cancers affecting the bone marrow. It is usually unknown what causes myelodysplastic syndromes.

Contents

Definition & Facts

Bone marrow is a spongy material within the bones which is responsible for making three different types of blood cells: red blood cells, white blood cells, and platelets. When the bone marrow is not functioning correctly, it may not be making enough new, healthy blood cells. Some of the blood cells may be formed poorly or may not function as they should, causing a group of disorders that are called myelodysplastic syndromes or MDS.

Symptoms & Complaints

When myelodysplastic syndrome is in its early stages, there are rarely any symptoms that will be seen. Over a period of time as the syndrome progresses, some of the symptoms may include:

Causes

There are two different categories that doctors have split MDS into based on causal factors. The first has no known cause. Doctors are unsure of what causes myelodysplastic syndrome in these cases, but they are often more easily treated than those cases that have a known cause.

The second category are those cases that have a known cause. Some patients can develop MDS due to a response their body has to cancer treatment, either radiation therapy or chemotherapy, or due to a response to some type of exposure to chemicals. This category is called secondary myelodysplastic syndrome, which is typically more difficult to treat than MDS without a known cause.

Along with dividing MDS into categories based on cause, MDS is also divided into different types based on the type of blood cells that are involved:

  • Refractory cytopenia with unilineage dysplasia. This type of MDS involves a low amount of just one of the blood cell types. When looked at under a microscope, the abnormality in the cells can be seen.
  • Refractory anemia with ring sideroblasts. In this type, the amount of red blood cells is low. The red blood cells that have been created carry iron deposits called ringed sideroblasts.
  • Refractory cytopenia with multilineage dysplasia. Two of the different blood cells are involved and are abnormal in this type.
  • Refractory anemia with excess blasts. Types 1 and 2-Both of these types will have abnormalities in one or more types of blood cells. When looked at under a microscope, the abnormality in the cells can be seen.
  • Myelodysplastic syndrome, Unclassified. This type is quite uncommon, but any of the three blood cell types will be low. When looked at under a microscope, either the platelets or the white blood cells will look abnormal.
  • Myelodysplastic syndrome associated with isolated del(5q) chromosome abnormality. The amount of red blood cells will be low in this type and they will also have a specific DNA mutation.

Diagnosis & Tests

If MDS is suspected to be the cause of a patient's symptoms, doctors will complete tests in order to determine if MDS is the cause as well as completing tests to rule out other disorders or illnesses that have similar symptoms. These tests include:

  • Blood tests. These may be completed in order to get a complete count of the patient's blood cells. At the same time, they will look for any type of abnormality in the shape, size, or appearance of the blood cells.
  • Bone marrow tests. A sample of the patient's bone marrow as well as a small piece of bone will be taken from the back of the hip bone. These samples will then be sent off to a laboratory where they will be examined for abnormalities.

Treatment & Therapy 

The different treatments used for MDS attempt to slow the progression of the disorder as well as mitigate symptoms that come along with it. Blood transfusion may be used in order to replace the unhealthy blood cells with healthy blood cells.

There are also a number of medications that may be used in order to get the body to produce blood cells that are healthy. Medications that are used to increase the production of blood cells are also called growth factors. They will help to reduce the chance of needing a blood transfusion by creating more red blood cells. They can also help create more white blood cells, reducing the risk of infection. These medications include darbepoetin alfa and epoetin alfa.

Additional medications prescribed to treat this disorder include decitabine, azacitidine, and lenalidomide.

Prevention & Prophylaxis

There are currently no known ways to prevent MDS. Chemotherapy and radiation are extremely important treatments that are used for those that have been diagnosed with cancer. But these treatments have been found to be a cause of MDS. Doctors are currently studying MDS and working on finding ways to try and reduce the risk of getting MDS after receiving treatments for cancer.