Myelodysplastic syndrome is a form of blood and/or bone cancer that involves abnormal cells in the bone marrow. According to the Leukemia & Lymphoma Society, there are approximately 10,000 cases of myleodysplastic syndromes diagnosed annually. Although they are all considered to be a cancer, there are both high and low risk forms of MDS syndromes, as well as a specific form of leukemia (called AML) which is caused by MDS syndromes.
Types of Myelodysplastic Syndromes
Treatment for MDS depends in large part on the type of MDS. MDS interferes with the production of blood cells and platelets in the bone marrow. In healthy people, blood cells and platelets and produced, and at any given time, only 5 percent or fewer cells within the bone marrow are immature and not properly produced. These immature cells are called blasts. However, in MDS patients, the number of blasts rises above 5 percent.
In low-risk MDS patients, the number of blasts is above 5 percent but is not high enough to cause severe medical problems. Low-risk MDS is slow-growing, and the most common effect of the disease is anemia.
High-risk MDS patients, on the other hand, have higher levels of blasts, and these blasts are released into the bloodstream instead of mature white blood cells, red blood cells and platelets. The higher number of blasts begins to cause health problems, and can be fatal. Once the number of blasts reaches 20 percent or higher, the patient is said to have AML---acute myelogenous leukemia.
Treatment for Low-Risk MDS
Often, low-risk MDS is not treated. Doctors simply apply a watch-and-wait attitude, monitoring the growth of the cancer and the blood cell counts. Patients routinely visit a doctor to get a complete blood cell count taken, to ensure that the levels of red blood cells, white blood cells and platelets is at a normal level. If the blood cell count drops to a dangerous level, blood transfusions or platelet transfusions are given.
Blood Cell Growth Factors
Some patients, both with high- and low-risk MDS, are treated with medications that affect blood cell growth. One common blood cell growth factor is injections of erythropoietin-stimulating agents (ESAs). These ESAs help stimulate production of a hormone called EPO which is located in the kidneys and is responsible for the growth of red blood cells. ESAs, including Procrit and Aranesp, are given by injection.
G-CSF or GM-CSF are also given by injection. These growth factors are designed to stimulate white blood cell growth in the body.
As of 2009, another growth factor called AMG 531 is under clinical trials to stimulate platelet growth.
Drug Treatment
Some high- and low-risk MDL patients are also candidates for various drug treatments. Azacitidine has been demonstrated to be effective in 40 percent of patients in helping bone marrow to function normally and killing cells within bone marrow that produce blasts. This drug is given by injection, but as of 2009, an oral version is being developed.
Decitabine is another injectible drug given to both high- and low-risk patients, which improves blood cell count levels in between 30 and 40 percent of patients.
Lenalidomide is a form of drug therapy for MDS patients who also have anemia. Lenalidomide is usually recommended for low-risk patients, and can enable between 20 and 30 percent of low-risk patients to eliminate the need for red blood cell transfusions for as long as two years.
Chemotherapy and Allogenic Stem Cell Replacement
High-dose chemotherapy and stem cell replacement are appropriate only in certain instances. First, this treatment method is only recommended for high-risk patients and/or patients with AML. Because it is a risky therapy, it is only recommended in cases where the patient has a short life expectancy without the treatment. Furthermore, the patient must have an allogenic match---a perfectly matched donor---for the stem cell therapy to be effective.
Tags: blood cells, blood cell, bone marrow, low-risk patients, blood cells platelets