Myelodysplastic syndromes, or MDS, are a group of diseases of blood and bone marrow. Blood stem cells originate in bone marrow; after maturation they become white or red blood cells, or platelets. In MDS, the stem cells do not mature and they remain immature blast cells, either dying or not functioning normally. These immature cells accumulate and do not allow room for healthy mature cells to enter the blood, leading to MDS. The American Cancer Society notes that 1 in 3 people who have MDS will develop a bone marrow cancer called acute myeloid leukemia.
Incidence
The American Cancer Society estimates that each year in the United States between 10,000 and 15,000 new cases of MDS are diagnosed. They state that 80 to 90 percent of individuals who are diagnosed are older than 60 years old, and as the population becomes older as a whole, the incidence of MDS is slowly increasing.
Risk Factors
The exact cause of MDS is not known, but there are several risk factors that increase the chance to develop one of the associated diseases. The American Cancer Society lists the primary risk factor as having had prior chemotherapy treatment, especially combined with radiation therapy; smoking cigarettes; environmental risk factors like radiation exposure or exposure to certain chemicals; older age; and genetic syndromes such as Fanconi anemia, Shwachman-Diamond syndrome and familial platelet disorder.
Symptoms
In the early stages of MDS, there are few symptoms; as the disease progresses, an individual may become symptomatic. Indications can include fatigue, shortness of breath, extreme paleness, easy bruising or unusual bleeding, frequent infections and small red spots just underneath the skin, called petechiae. These symptoms are due to the low levels of red blood cells, platelets and white blood cells that occur as a result of MDS.
Types
Types of MDS include refractory anemia, or RA; RA with ringed sideroblasts; RA with excess blasts; RA with excess blasts in transformation; refractory cytopenia with multilineage dysplasia; MDS with a chromosome abnormality; and unclassifiable MDS. The type of MDS is determined by examining the blood microscopically and looking at the appearance of the blood cells and any chromosome changes on the cells.
Treatment
There are different kinds of treatment for MDS, depending on the type of MDS and its response to different treatment modalities. Treatment options include supportive care with blood transfusions to help patients deal with fatigue from anemia, along with erythropoietin to stimulate red blood cell growth; high-dose chemotherapy followed by a donor stem-cell transplant; and growth factor therapy with granulocyte colony stimulating factor, or G-CSF and sargramostim, to help build up white blood cells, which can help fight infection.
References
- American Cancer Society: Key Statistics About Myelodysplastic Syndrome?
- American Cancer Society: What are the Risk Factors for Myelodysplastic Syndrome?
- National Cancer Institute: General Information About Myelodysplastic Syndrome
- National Cancer Institute: Myelodysplastic Syndromes Treatment
- American Cancer Society: Growth Factors
