Symptoms, Diagnosis, & Risk Factors
In the early stages of myelodysplastic syndrome (MDS), many people have no symptoms. But a routine blood test may show low levels of red blood cells (RBCs), white blood cells (WBCs), or platelets.
Some people have symptoms related to their low blood counts. Symptoms can range from mild to severe and can vary greatly from patient to patient. Of course, other conditions besides MDS can cause these symptoms. If you have these symptoms, it’s important to see a doctor to find the cause.
Symptoms related to low RBCs (anemia) may include the following:
- Shortness of breath
- Paler skin than usual
- General malaise
- Rapid heart beat
Symptoms related to low WBCs (leukopenia) may include the following:
- Frequent infections
- Infections that won’t resolve
Symptoms related to low platelets (thrombocytopenia) may include the following:
- Easy bruising
- Unexplained bleeding
To find out whether you have MDS, your doctor will first do a thorough physical exam and ask about your health history and any symptoms.
Next your doctor will perform a series of blood tests to tell whether any blood cells are abnormal and, if so, which ones. Common blood tests include the following:
- Complete blood count (CBC): determines how many cells of each type are circulating in the bloodstream
- Peripheral blood smear: looks at the appearance of the blood cells
- Blood chemistry: looks for abnormalities in the blood, including certain enzymes or abnormal iron level
Bone Marrow Aspiration and Biopsy
For a definitive diagnosis, doctors generally need to perform a bone marrow aspiration and biopsy. A small area of skin over your lower back (pelvis) is cleaned and numbed. Then a marrow needle is used to withdraw bone marrow. If a biopsy is performed, the doctor uses a different needle to take a small piece of marrow from your bone (a marrow core). In either case, the sample will be examined under a microscope to determine the presence and number of abnormal cells in your marrow.
In addition, doctors will perform cytogenetic analysis. This means your marrow cells will be set up in a culture dish to make them divide. This will allow us to see your chromosomes under a microscope and tell whether any are abnormal. Doctors use the number and type of chromosome abnormalities to help predict how your disease will progress and which types of treatment might be most effective. Your chromosomes contain your genes and can provide instructions for how your cells function.
Fluorescent in situ hybridization (FISH) is a specialized cytogenetic analysis. The fluorescent dyes used in this test attach to specific parts of certain chromosomes. More chromosomal abnormalities can be seen under a microscope using this technique than with the standard technique described above.
You may also have flow cytometry (a computer analysis of cells) and other tests that are being developed to establish a more accurate MDS diagnosis.
Doctors don’t know what causes the cellular changes that lead to MDS. Sometimes MDS develops in people who have been treated with chemotherapy or radiation for another illness or who have been heavily exposed to certain chemicals. In these cases, MDS is referred to as secondary MDS or treatment-related MDS. If none of those conditions is present, doctors call it primary MDS or de novo MDS.
It’s not clear at this time what other factors may cause MDS. Exposure to toxins, such as benzene, certain solvents or pesticides, and heavy metals, such as mercury or lead, may be involved. Some data suggest that smoking tobacco increases the risk of MDS. It is extremely difficult, if not impossible, to establish a clear cause-and-effect relationship between those exposures and the development of MDS.
So far there has been no good epidemiologic study in the United States to better define factors that are important in the development of MDS. (Epidemiology is the study of how common a disease is, how the disease is distributed, and how it might be controlled in a population.) Researchers at Seattle Cancer Care Alliance and Fred Hutchinson Cancer Research Center have conducted studies to compare people without MDS to people with MDS to learn more about factors that may increase risk for the disease. We invite you to talk with your doctor about whether you can participate in any such studies.
MDS is more common in men than in women. The incidence of MDS increases throughout adulthood, and it is most common after the age of 50. About 80 percent of people with MDS are over age 60. Advanced age sometimes complicates treatment of MDS because older people are more likely to have other health problems, too. Children can develop MDS; most who do develop MDS have some other genetic disease.