Myelodysplastic Syndrome with Excess Blasts
Myelodysplastic syndrome with excess blasts is a high-risk form of a blood disorder where the bone marrow produces too many immature blood cells and not enough healthy ones, often leading to serious complications.
Table of contents
- What is myelodysplastic syndrome with excess blasts?
- The bone marrow and blood cell production
- Two types of MDS-EB
- Signs and symptoms
- Who is more likely to develop MDS-EB
- How doctors diagnose MDS-EB
- Disease progression and outlook
- Treatment options
MDS-EB1, MDS-EB2, MDS with Excess Blasts, RAEB, Refractory Anemia with Excess Blasts
D46.2; D46.9
What is myelodysplastic syndrome with excess blasts?
Myelodysplastic syndrome with excess blasts (MDS-EB) is a subtype of myelodysplastic syndrome, which refers to a group of cancers that affect blood stem cells. In MDS-EB, the bone marrow contains a higher number of immature blood cells called blasts. These blasts are very early forms of blood cells that have not yet matured into functioning red blood cells, white blood cells, or platelets.[1][2]
When you have MDS-EB, your body cannot make enough healthy blood cells because the blasts take up space in the bone marrow where healthy cells should be growing. This leads to low numbers of at least one type of blood cell in your body. The early forms of cell types in the bone marrow may or may not look abnormal under the microscope.[6]
MDS-EB is considered a high-risk form of myelodysplastic syndrome because it has an increased likelihood of progressing to acute myeloid leukemia (AML), a more serious type of blood cancer. About 40% of people diagnosed with MDS-EB eventually develop AML.[4][11]
- Bone marrow
- Blood
The bone marrow and blood cell production
Your bones support and frame your body. Inside them is a spongy material called bone marrow, which is where blood cells are made. In a healthy person, the bone marrow makes blood stem cells, which are immature cells that develop into mature blood cells over time.[7]
The bone marrow should make three main types of blood cells. Red blood cells carry oxygen and other substances to all tissues of the body. White blood cells are key elements of your immune system and help fight infection and disease. Platelets help your blood to clot and stop bleeding.[7]
In a patient with myelodysplastic syndrome with excess blasts, the blood stem cells do not become mature red blood cells, white blood cells, or platelets in the bone marrow. These immature blood cells, called blasts, do not work the way they should. They either die in the bone marrow or soon after they go into the blood. This leaves less room for healthy white blood cells, red blood cells, and platelets to form in the bone marrow.[7]
Two types of MDS-EB
MDS-EB is classified into two types based on how many of the cells in the bone marrow or blood are blasts.[6]
MDS-EB1: In this type, blasts make up 5% to 9% of the cells in the bone marrow, or 2% to 4% of the cells in the blood. Five percent to 19% of the cells in the bone marrow are blasts. There also may be changes to the white blood cells and platelets.[6][7]
MDS-EB2: Blasts make up 10% to 19% of the cells in the bone marrow, or 5% to 19% of the cells in the blood. This type has a higher risk of becoming acute myeloid leukemia.[6]
Signs and symptoms
People with myelodysplastic syndrome with excess blasts might not experience signs and symptoms at first. In time, MDS-EB can cause a range of symptoms depending on which type of blood cell is most affected.[1][14]
Many people with MDS-EB have a low red blood cell count called anemia. This can cause constant fatigue, shortness of breath, and unusual paleness. You might feel weak and tired even after resting.[1][6]
A low white blood cell count, called neutropenia or leukopenia, means your body has fewer cells to fight infections. This can lead to frequent infections that may be difficult to treat.[1][6]
A low platelet count, called thrombocytopenia, affects your blood’s ability to clot. This can cause easy or unusual bruising and bleeding. You might notice pinpoint-sized red spots just beneath the skin called petechiae, which are caused by bleeding under the skin.[1][6]
Who is more likely to develop MDS-EB
Myelodysplastic syndromes affect males slightly more often than females. The disorder occurs in all age groups, but is far more common in older adults. MDS occurs most often in individuals over 60 years of age, with a median age at diagnosis of approximately 70 years. According to one estimate, 22 to 45 per 100,000 people over the age of 70 years have MDS.[6][9]
Some cases of MDS-EB are linked to known risk factors. These factors lead to changes in the DNA in bone marrow cells which may cause MDS-EB to develop, but most often, the cause is unknown. You might be more likely to get MDS-EB after treatment for cancer. You can get this syndrome 1 to 15 years after receiving certain forms of chemotherapy or radiation therapy. This is sometimes called treatment-related MDS.[3][6]
Other risk factors include smoking and having a genetic syndrome that increases the chance of developing MDS.[6]
How doctors diagnose MDS-EB
The diagnosis of MDS-EB is made through several tests. Your doctor will start with a history and physical examination. They will then order a complete blood count (CBC) to measure the levels of different blood cells in your blood.[6]
An examination of your blood smear and a bone marrow aspiration and biopsy are essential tests. During a bone marrow biopsy, a small sample of bone marrow is removed, usually from your hip bone. Doctors examine this sample under a microscope to see how your bone marrow cells look and to count how many blasts are present.[5][6]
Genetic testing is also performed on the bone marrow sample. Special tests analyze the cells to look for chromosome changes and gene mutations. Examples of chromosome changes that are found in MDS cells include a deletion of the q-arm in one or more of chromosomes 5, 7 and 20, or an extra copy of chromosome 8. Examples of gene mutations include SF3B1 and TP53.[5][6]
Disease progression and outlook
MDS-EB has a high likelihood of turning into acute myeloid leukemia. Although the actual number varies within medical literature, most state that between 5% to 29% of cases of MDS-EB deteriorate into AML. The transition to leukemia is accompanied by worsening bone marrow function and the accumulation of undeveloped immature cells called blasts, first in the marrow and subsequently in the blood. These blasts have no useful function and suppress any remaining marrow cell production.[5][6]
As a consequence, the complications from anemia, bleeding, and infection become life-threatening. Survival for MDS-EB is short, with median survival less than two years.[6]
The prognosis for patients with MDS is highly variable and is influenced by factors such as chromosome abnormalities and the severity of low blood cell counts. Specifically, patients exhibiting the 5q chromosomal deletion tend to have a more favorable prognosis compared to those with monosomy 7.[3]
Treatment options
Treatment of MDS-EB may include several different approaches. The goal of treatment is to slow the disease, ease symptoms, prevent complications, and help you to live longer.[1][6]
Blood transfusions are a common part of treatment. Patients with low red blood cell counts may require red blood cell transfusions to help with anemia and fatigue. If platelet counts are low, platelet transfusions may be needed to prevent bleeding.[6][13]
Supportive care is important for managing symptoms. This includes treating infections when they occur and providing medications to boost blood cell production.[1][6]
Chemotherapy is used in patients with MDS who have increasing numbers of blasts. The usual combination treatment includes medications that help destroy abnormal cells. Treatment with drugs called hypomethylating agents is considered standard therapy for MDS-EB. This approach is especially useful in elderly patients, who may have difficulty tolerating more aggressive chemotherapy.[13]
A bone marrow transplant, also known as a stem cell transplant, may be recommended in certain situations. This procedure replaces your bone marrow with healthy bone marrow from a donor. This is the only potential cure for MDS, but it is a complex procedure with risks. It is typically reserved for younger and fit patients with high-risk disease.[1][6][13]
Not all patients require treatment initially. There is no survival benefit with the treatment of patients who have no symptoms and low-risk disease. Treatment is reserved for patients who are symptomatic, such as those requiring frequent blood transfusions.[3]