With the myelodysplastic syndrome (MDS) the precursors of the white blood cells, the red blood cells and the platelets are defective to various degrees. Depending how severe the blockage of the maturation process is, the disease can be mild or more severe. MDS is a group of syndromes often seen in patients older than 50 years. In some patients there may be a history of benzene exposure or radiation exposure.
The hall mark of this syndrome is that immature bone marrow stem cells (hematopoietic stem cells) of a certain lineage (red blood cells, white blood cells or platelet precursor cells) suddenly decide to multiply in the sense of cell clones. This means that one type of cell suddenly takes off by producing millions of “look-alikes”. A high percentage of the MDS patients convert into AML. The response of MDS and AML to chemotherapy shows a survival, which is very similar, supporting the belief that MDS may largely be a precursor of AML, although there are other leukemias lumped in such as Philadelphia negative CML, refractory anemias and some other more rare hematological disorders. A hematologist needs to be involved in all of these diseases.
Symptoms
The symptoms depend on the underlying subgroup. The symptoms in the beginning may be fatigue and weakness when there is an anemia present.
If there are low platelets in the bone marrow, bleeding might occur. With a low white blood cell count, fever and infections would be in the foreground.
Non specific symptoms such as anorexia, weight loss and in the presence of an enlarged spleen and a swollen abdomen would be present.
Tests
Blood test results vary depending on which subtype is present. There would be grossly abnormal blood test findings in one case, and more subtle changes in another case. Any such case should be referred to a hematologist, as further tests including bone marrow tests need to be done to classify exactly what is going on.
Treatment and Prognosis
For treatment options, which are quite limited at this point and which depend on the subtype present, the patient should rely on the advice of a hematologist. The prognosis is quite varied depending on what type of underlying diagnosis is present. The following table shows some typical survival data from the literature (Ref. 1 and 2):
Classification of MDS (myelodysplastic syndrome)
| Subtypes of MDS: | Median survival: (years) |
|---|---|
| Refractory anemia | 5 |
| Refractory anemia with excess blasts | 1.5 |
| Chronic myelomonocytic leukemia | 1.5 |
| Refractory anemia with excess blasts in transformation | 0.5 |
There is no established treatment at the present time for MDS. Myelodysplastic syndrome treatment is supportive with blood transfusions, platelet transfusions and antibiotic therapy. However, this is a very complex disease entity, which needs the input and advice of an experienced hematologist to manage it.
References
1. Cancer: Principles &Practice of Oncology. 4th edition. Edited by Vincent T. DeVita, Jr. et al. Lippincott, Philadelphia,PA, 1993. Chapter on Chronic Leukemia.
2. Cancer: Principles&Practice of Oncology. 5th edition, volume 2. Edited by Vincent T. DeVita, Jr. et al. Lippincott-Raven Publ., Philadelphia,PA, 1997. Chapter on Chronic Leukemia.
3. BJ Druker et al. N Engl J Med 2001 Apr 5;344(14):1031-1037.
4. MJ Mauro et al. Curr Oncol Rep 2001 May;3(3):223-227.
5. Conn’s Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier
6. Ferri: Ferri’s Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc
