Wednesday, February 13, 2013

Myelodisplastic Syndromes

MDS refers to a condition in the blood and bone marrow that is characterized by abnormal cells in the bone marrow, and low blood-cell count. It is more common in men then women, and most often afflicts men over the age of 70. The Leukemia & Lymphoma Society states that between 2001 and 2005, 50,484 cases of MDS were diagnosed within the United States. Using these numbers, the Leukemia & Lymphoma society estimates that an average of 10,000 new MDS cases are diagnosed each year.


What is MDS?


MDS is a disorder of the bone marrow that results in problems with blood-cell count. Cells develop in the bone marrow into white blood cells, red blood cells and platelets. These blood cells serve important functions within the body--like carrying oxygen and fighting infection, among other things. Everyone has some immature cells within the bone marrow that have not, and do not, develop properly into a white or red blood cell or a platelet. Normally, the number of immature cells--called blasts--is at or below five percent. In patients with MDS, a higher number of blasts occurs because cells fail to develop properly.


Types of MDS


There are two major types of MDS, high-risk MDS and low-risk MDS. Patients with low-risk MDS have abnormal cells in the bone marrow, but the majority of their cells are normal. While low-risk MDS patients have blast levels above the normal five percent, the blast levels are generally not high enough to create serious health problems. Many low-risk MDS patients have anemia, but are able to manage this and any other symptoms of MDS well. High-risk MDS patients, on the other hand, have a higher number of blasts that are released into the blood stream. Their cells may not function normally, they may have very low blood-cell counts, and serious side effects may occur, up to and including fatality.


Is MDS a Cancer?


MDS is considered to be a cancer, in the sense that the cells in the bone marrow are abnormal. However, not all MDS syndromes are a form of leukemia. Although high-risk MDS can be fatal in its own right, it is distinct from MDS-related leukemia, called Acute Myelogenous Leukemia or AML. Only patients with a blast level higher than 20 percent are considered to have acute MDL.








What Causes MDS & How is it Diagnosed


Primary MDS, the most common myelodisplastic syndrome, has no known cause in many cases. However, repeated exposure to a chemical called benzine, which is found in cigarettes and some industrial settings, has been linked with the development of MDS. Secondary MDS may be caused by other cancer treatments, including radiation and chemotherapy. Secondary MDS is rare, even in patients who have undergone these cancer treatments, and the Leukemia & Lymphoma Society suggests that patients who are diagnosed with secondary MDS may have had an underlying genetic condition that made their bodies more predisposed to developing treatment-related MDS.


Because MDS is largely asymptomatic, and the symptoms associated with it--fatigue and shortness of breath--can have many causes, MDS is primarily diagnosed as part of a routine physical that includes a CBC (complete blood-cell count). A conclusive diagnosis involves measuring blood-cell counts, and observing blood cells and bone marrow under a microscope.


What Treatments Are Available?


Treatment varies depending on the type of myelodisplastic syndrome. Low-risk MDS patients may simply watch and wait, monitoring symptoms and treating low blood-cell counts with blood transfusions. High-risk patients, and/or patients with AML, may be treated with high-dose chemotherapy. When possible, an allogenic stem cell transplant can be useful in managing MDS, but the procedure is risky and requires a matched donor.

Tags: bone marrow, blood cells, cells bone, cells bone marrow, blood-cell count, blood-cell counts, bone marrow that