Myelodysplastic Syndromes (MDS) are a group of diverse bone marrow disorders in which the bone marrow does not produce enough healthy blood cells. MDS is often referred to as a “bone marrow failure disorder”. MDS is primarily a disease of the elderly (most patients are older than age 65), but MDS can affect younger patients as well. To help you better understand MDS, it might be helpful to first consider some basics about bone marrow and blood. The bone marrow functions as a factory that manufactures three kinds of blood cells: red blood cells, white blood cells, and platelets. Healthy bone marrow produces immature blood cells — called stem cells, progenitor cells, or blasts — that normally develop into mature, fully functional red blood cells, white blood cells, and platelets. In MDS, these stem cells may not mature and may accumulate in the bone marrow or they may have a shortened life span, resulting in fewer than normal mature blood cells in the circulation.
Low blood cell counts, referred to as cytopenias, are a hallmark feature of MDS and are responsible for some of the symptoms that MDS patients experience — infection, anemia, spontaneous bleeding, or easy bruising. Anemia (low red blood cell counts), neutropenia (low white blood cell counts), and thrombocytopenia (low platelet counts) are the major types of blood cell cytopenias, and are discussed below. In addition to reduced numbers of blood cells, the mature blood cells circulating in the blood may not function properly because of dysplasia. The formal definition of dysplasia is the abnormal shape and appearance, or morphology, of a cell. The prefix myelo- is from the Greek and it means marrow; so myelodysplasia refers to the abnormal shape and appearance — or morphology — of the mature blood cells. Syndromes comes from the Greek and means a set of symptoms that occur together.
Failure of the bone marrow to produce mature healthy cells is a gradual process, and therefore MDS is not necessarily a terminal disease. Some patients do succumb to the direct effects of the disease: reduced blood cell and/or reduced platelet counts may be accompanied by the loss of the body’s ability to fight infections and control bleeding. In addition, for roughly 30% of the patients diagnosed with MDS, this type of bone marrow failure syndrome will progress to acute myeloid leukemia (AML).
To read more about the effects of MDS on blood cells, click here to view our complete handbook.
Myelodysplastic syndromes (MDS) are an often unrecognized, under-diagnosed rare group of bone marrow failure disorders, where the body no longer makes enough healthy, normal blood cells in the bone marrow. The disease is also known as a form of blood cancer.
new cases of MDS are reported every year in the U.S., with an average of 33-55 people diagnosed in the U.S. every day.
are estimated to live with MDS in the U.S. with an estimated 87,000 new cases each year worldwide.
75% of MDS patients are 60+ years of age, and the disease also can affect children and young adults
MDS patients (or 30%) progress to acute myeloid leukemia (AML).
is the average survival rate for lower risk patients (who do not receive a bone marrow transplant) and approximately 5 months for high-risk patients.
The exact causes of MDS are unknown. Potential triggers include:
Radiation and chemotherapy for cancer.
Long-term exposure to certain environmental or industrial chemicals, such as benzene.
A stem cell transplant is considered the only way to potentially cure MDS.
Approved treatments are available to help treat the symptoms and help to slow the progression of the disease.
With a few exceptions, the exact causes of MDS are unknown. Some evidence suggests that certain people are born with a tendency to develop MDS. This tendency can be thought of as a switch that is triggered by an external factor. If the external factor cannot be identified, then the disease is referred to as “primary MDS”.
Radiation and chemotherapy for cancer are among the known triggers for the development of MDS. Patients who take chemotherapy drugs or who receive radiation therapy for potentially curable cancers, such as breast or testicular cancers, Hodgkin’s disease and non-Hodgkin’s lymphoma, are at risk of developing MDS for up to 10 years following treatment. MDS that develops after use of cancer chemotherapy or radiation is called “secondary MDS” and is usually associated with multiple chromosome abnormalities in cells in the bone marrow. This type of MDS often develops rapidly into AML.
Long term exposure to certain environmental or industrial chemicals, such as benzene, can also trigger MDS. While benzene use is now highly regulated, it is not clear which other chemicals may predispose individuals to MDS, although certain occupations have been labeled “at risk” for the development of MDS or AML (e.g., painters, coal miners, embalmers). There are no known food or agricultural products that cause MDS. While alcohol consumed on a daily basis may lower red blood cell and platelet counts, alcohol does not cause MDS. There is insufficient data available to determine if smoking increases the risk of developing MDS. However, it is known that the risk of developing AML is 1.6 times greater for smokers than for non-smokers.
Patients and their families often worry that MDS might be contagious. No evidence exists to suggest that a virus causes MDS; thus, MDS cannot be transmitted to loved ones.
MDS is not inherited. In fact, it is a very rare occasion when family members, including siblings, are diagnosed with MDS.
In the early stages of MDS patients may experience no symptoms at all. A routine blood test may reveal a reduced red cell count, or low hematocrit, sometimes along with reduced white cell and/or reduced platelet counts. On occasion, the white cell and platelet counts may be low while the hematocrit remains normal. However, some patients, particularly those with blood cell counts well below normal, experience definite symptoms. These symptoms, described below, depend on which blood cell type is involved as well as the level of the cell count.
The majority of individuals are anemic when they are initially diagnosed with MDS. Anemia is characterized by a persistently low hematocrit (a measure of the body’s red blood cells) or persistently low levels of hemoglobin (the blood protein that carries oxygen to the body’s tissues). Anemic patients generally experience fatigue and report that they are tired much of the time and have no energy. Anemia varies in its severity. In mild anemia, patients may feel well or just slightly fatigued. In moderate anemia, almost all patients experience some fatigue, which may be accompanied by heart
palpitations, shortness of breath, and pale skin. In severe anemia, almost all patients appear pale and report chronic overwhelming fatigue and shortness of breath. Because severe anemia reduces blood flow to the heart, older patients may be more likely to experience cardiovascular symptoms, including chest pain. Although chronic anemia is seldom life threatening, it can drastically reduce a patient’s quality of life.
A reduced white cell count lowers the body’s resistance to bacterial infection. Patients with neutropenia may be susceptible to skin infections, sinus infections (symptoms include nasal congestion), lung infections (symptoms include cough, shortness of breath), or urinary tract infections (symptoms include painful and frequent urination). Fever may accompany these infections.
Patients with thrombocytopenia have an increased tendency to bruise and bleed even after minor bumps and scrapes. Nosebleeds are common and patients often experience bleeding of the gums, particularly after dental work. Before having dental work, consultation with your hematologist, who may prescribe the prophylactic use of antibiotics, is recommended since infection and bleeding pose a risk for most MDS patients.
There are many ways that you can support those diagnosed with MDS. You can learn more about MDS from our website, and by reading materials such as our Building Blocks of Hope program.
For more information, feel free to contact us directly.