|
 Myelodysplastic syndromes (MDS) occurs when the bone marrow and stem cells malfunction. This results in the production of too many defective blood cells and not enough normal blood cells.
History: Myelodysplastic syndromes (MDS) were first described in the early 1930s. They were not treated as a separate group of disorders until 1976.
Blood and bone marrow findings: Patients with myelodysplastic syndromes have low blood cell counts in at least one or more of the three blood lines - red blood cells, white blood cells, and platelets. Upon examination, the bone marrow usually is found to be hyperplastic, meaning there are too many poorly functioning blood stem cells in the marrow. A small percentage of MDS patients have hypoplastic bone marrow, meaning there are too few blood stem cells in the marrow, which make the disease look similar to aplastic anemia. Changes in the chromosomes occur in many patients with MDS.
Subtypes: There are several subtypes of MDS, mainly based on the percentage of immature blood cells, called blasts, in the marrow and in the bloodstream:
- Refractory anemia (RA)
- Refractory anemia with ringed sideroblasts (RARS)
- Refractory cytopenia with multilineage dysplasia (RCMD)
- Refractory anemia with excess blasts (RAEB-1 and RAEB-2)
- Myelodysplastic syndromes, unclassified (MDS-U)
- MDS associated with isolated del(5q)
Symptoms: Nearly half of people with MDS have no symptoms at time of diagnosis. When symptoms do occur they can include anemia, weakness, fatigue, headache, bruising, increased bleeding, rash, fevers, mouth sores and lingering illness.
Incidence and Diagnosis: MDS occurs at an increasing frequency in older people, but it can occur in children too. In less than a third of patients, MDS progresses over time to become acute leukemia. Diagnosis will be confirmed by first getting a Complete Blood Count (CBC) followed by a bone marrow biopsy. The average age of diagnosis is 70 years old. MDS is diagnosed in more than 10,000 people in the U.S. each year.
Treatments: Treatments for MDS may vary considerably.
- For older patients and those with milder forms of the disease, treatment is often supportive. A patient is given red blood cell transfusions to provide immediate relief from symptoms of anemia; platelet transfusions to reduce risk of bleeding and bruising; and growth factors such as Procrit or Epogen (erythropoietin) and Neupogen (granulocyte-colony stimulating factor) to stimulate blood cell production.
- There are currently three drugs approved for the treatment of MDS by the U.S. Food and Drug Administration. Vidaza (azacitidine) and Dacogen (decitabine) are approved for the treatment of all 5 subtypes of MDS. Revlimid (lenalidomide) is approved for low-to-intermediate MDS with the specific chromosomal deletion of 5q. Recent studies have reported remissions or partial remissions with the use of immunosuppressive drugs, decitibine, thalidomide, arsenic trioxide, retinoids, interferons, farnysyl transferase inhibitors, amifostine, valporic acid, topotecan, and/or hydroxyurea.
- More aggressive forms of myelodysplastic syndrome may evolve into leukemia. In these cases, treatment requires killing abnormal blood-forming cells with chemotherapy or through stem cell transplantation. Chemotherapy is successful in causing a remission in a minority of patients. However, improvements are often temporary. Stem cell transplantation replaces the defective bone marrow with healthy cells. Results depend on the subtype of myelodysplastic syndrome, the age of the patient, and the chromosome abnormalities that may be present. Stem cell transplantation has typically been used primarily for patients younger than 50 years old. However, they are increasing being used in patients into their 60's. Recent advances may increase the age range of patients likely to benefit from this procedure.
Ask your hematologist about all treatment options. Each AA&MDSIF Information Packet contains a Managing Treatment Decisions brochure which explains the information you need to make an informed decision that is right for you. It includes questions that need to be answered before you agree to any treatment option. To request a free copy of this information packet, please click here.
Overview of Bone Marrow Diseases
Bone Marrow and Blood Production
Aplastic Anemia
Paroxysmal Nocturnal Hemoglobinuria
Learn More About Your Disease
Glossary
Last Modified: November 10, 2006 |
|
