Myelodysplastic syndrome is a heterogeneous group of hematologic disorder affecting bone marrow hematopoiesis leading to reduced number of mature blood cells known as peripheral blood cytopenias. Myeloid stem cell lineage is affected involving one or all of the cell lineages leading to reduced number of red blood cells, white blood cells and/or platelets. It is considered a premalignant condition and found usually in older adults with a median age of 70 years. It is more prevalent in males than in females.
How Do Myelodysplastic Syndrome Patients Die?
The cause of death in patients with myelodysplastic syndrome is attributed to acute myeloid leukemia, disease progression, infections and bleeding. Additional causes of death included heart failure; hemochromatosis and some causes are unclear. In a study of 2877 patients, 46.6% died due to AML, 27.0% died due to infection, 9.8% died due to bleeding, 16.6% died due to causes unrelated to myelodysplastic syndrome and in 42.1% cases the cause of death could not be determined.
In another study of 200 patients, 64.5% patients were low risk patients whereas 32.5% were high risk patients. 77% of these patients died of MDS related causes whereas 23% died of non-MDS related causes. In low risk patients, the causes of death were in descending order related to AML evolution, disease progression, infection and bleeding. Non-MDS related causes were secondary malignancy, ischemic stroke, acute myocardial infarction, congestive heart failure and others. In high risk groups, the cause of death in descending order was attributed to AML evolution, infection, and bleeding and disease progression. Non-MDS related causes included secondary malignancy, congestive heart failure and accidental.
Myelodysplastic syndrome occurs when there is decreased myeloid stem cell formation. It is considered to be both primary (de novo) in 80-90% cases or secondary (10-15% cases) to various factors, including exposure to prior radiation, chemotherapy (alkylating agents, topoisomerase II inhibitors), chemicals (benzene) and viral infection. Familial cases of myelodysplastic syndrome are also noted, but are very rare. (2)
Symptoms Of Myelodysplastic Syndrome
The clinical manifestations of myelodysplastic syndrome are due to anemia, thrombocytopenia and neutropenia. Anemia causes fatigue, malaise, weakness, pallor, increased somnolence, headaches, irritability, dizziness, palpitations and tachycardia. Neutropenia is associated with decreased immunity and increased chances of infection.
Thrombocytopenia leads to increased chances of bleeding. Splenomegaly is also noted in patients with chronic mylomonocytic leukemia (CMML).
Treatment Of Myelodysplastic Syndrome
For lower risk patients, the mainstay of treatment is supportive care, in addition to RBC and platelet transfusion and antibiotics for infections. Iron overload is managed with deferoxamine (sc) or deferasirox (oral). In addition, erythropoiesis-stimulating agents and granulocyte colony stimulating factor should be used in patients without del(5q); and lenalidomide in patients with del(5q). Azacitidine/decitabine or immunosuppressive therapy can be considered in cases of neutropenia and thrombocytopenia.
The management of higher risk MDS patients includes allogeneic hematopoietic stem cell transplant. Azacitidine or decitabine can be used in non-transplant candidates or for candidates with relapse or no response to transplantation.
Prognosis Of Myelodysplastic Syndrome
The revised International Prognostic Scoring System (IPSS-R) classifies patients into five groups, which include very low risk, low risk, intermediate risk, high risk and very high risk. The median survival of the patients with very low risk is 8.8 years; low risk patients have a median survival of 5.3 years and transformation to acute myeloid leukemia (AML) takes 10.8 years; intermediate risk patients have a median survival of 3.0 years and 3.2 years for AML transformation; high risk patients have a median survival of 1.6 years and about 1.4 years to transition to AML; very high risk patients have a median survival of 0.8 years and about 0.7 years to transition to AML.
The French-American-British (FAB) group has classified MDS into five types, Refractory Anemia (RA), Refractory Anemia with Ringed Sideroblasts (RARS), Refractory Anemia with Excess Blasts (RAEB), Refractory Anemia with Excess Blasts with transformation to AML (RAEB-T) and Chronic Myeloid Monocytic Leukemia (CMML). The rate of transformation for each subtype to AML is different having 10-20% rate for RA and RARS, 20-30% for CMML, 40-50% for RAEB and 60-75% for RAEB-T. (1) (3)
- Montoro, J., Vallespi, T., Sancho, E., Salamero, O., Lopez-Andreoni, L., sanchez-Morata, C., Navarrete, M., Ortega, M., Bobillo, S., Valdez, N., Bosch, F., & Valcárcel, D. (2011). Study of Causes of Death in Patients with Myelodysplastic Syndrome: A Single Institution Experience. Blood, 118(21),5`026. http://www.bloodjournal.org/content/118/21/5026
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- Myelodysplastic Syndromes: Staging, Risk Factors, Complications, Diagnosis
- Myelodysplastic Syndromes Treatments: Chemotherapy, Immunotherapy, Bone Marrow Transplant
- Myelodysplastic Syndromes or MDS: Treatment for Side Effects, Children with MDS
- Myelodysplastic Syndromes: Survival Rates, Prognosis, Recurrence, Remission, Lifestyle Changes, Prevention
- Coping with Myelodysplastic Syndromes & its Follow-Up Care