Myelodysplastic Syndrome
Myelodysplastic syndrome is a group of disorders that disrupts normal blood cell production in the bone marrow, leaving the body without enough healthy blood cells to function properly. While some people live with the condition for years without treatment, others may see it progress to a more aggressive form of cancer.
Table of contents
- What is myelodysplastic syndrome?
- Types of myelodysplastic syndrome
- Causes and risk factors
- Signs and symptoms
- Diagnosis and testing
- Treatment approaches
- Outlook and prognosis
- Living with myelodysplastic syndrome
What is myelodysplastic syndrome?
Myelodysplastic syndrome, also called myelodysplasia or MDS, is a group of cancers that affect how your bone marrow creates blood cells[1][2]. Your bone marrow is the spongy material inside your bones where blood cells are made[1].
myelodysplasia, myelodysplastic neoplasm, pre-leukemia, bone marrow failure disease
In a healthy person, the bone marrow produces blood stem cells, which are immature cells that develop over time into mature, working blood cells[8]. These stem cells can become red blood cells that carry oxygen, white blood cells that fight infections, or platelets that help your blood clot and stop bleeding[8].
When you have MDS, something goes wrong with this process. The blood stem cells don’t mature properly, and they either die in the bone marrow or soon after entering the bloodstream[6][8]. The cells that do form are often poorly shaped or don’t work as they should[1][3]. This leaves less room for healthy cells to develop, resulting in fewer healthy red blood cells, white blood cells, and platelets in your body[8].
MDS is rare, affecting about 4 in 100,000 people in the United States each year[2][11]. It occurs most often in older people, typically those over age 65, with a median age at diagnosis of about 70 years[3][11]. The condition affects men about twice as often as women[4].
- Bone marrow
- Blood
Types of myelodysplastic syndrome
There are six main types of MDS. Doctors categorize them based on how the blood and bone marrow cells look under a microscope, the number of healthy and immature blood cells, and changes in the cells’ chromosomes, which are the parts of cells that contain genes[2][4].
MDS with single lineage dysplasia (MDS-SLD) means that at least one type of immature blood cell or platelet in your bone marrow looks different from healthy cells[2]. Dysplasia means the cells are oddly shaped or appear different from normal cells. You have low levels of one or two blood cell types and the normal number of blasts, which are immature blood cells[2]. This type of MDS rarely develops into acute myeloid leukemia[2].
MDS with multilineage dysplasia (MDS-MLD) affects multiple types of blood cells or platelets in your bone marrow, making them look abnormal[2]. You have the normal number of blasts but low levels of at least one blood cell type. If you have this subtype, you may eventually develop acute myeloid leukemia[2].
MDS with ring sideroblasts (MDS-RS) occurs when about 15% of immature red blood cells are ring sideroblasts[2]. Sideroblasts are immature red blood cells that store iron instead of using it to make hemoglobin, a protein that helps red blood cells carry oxygen throughout your body[2]. This type rarely turns into acute myeloid leukemia[2].
MDS with excess blasts (MDS-EB) means you have a significant number of blasts in your bone marrow[2]. Tests show low levels of two of your three blood cell types. About 40% of people diagnosed with MDS-EB eventually develop acute myeloid leukemia[2].
Myelodysplastic syndrome associated with an isolated del (5q) chromosome is identified through special tests that show a certain part of chromosome 5 is missing[2][4].
Myelodysplastic syndrome, unclassifiable (MDS-U) describes cases where tests show you have fewer blood cells than usual or abnormal chromosomes, but no other clear MDS signs[2].
Causes and risk factors
MDS is a clonal disorder, meaning it starts from a single abnormal stem cell that multiplies[3]. The exact causes are often unknown, though some factors can increase your risk.
Many cases of MDS develop for no clear reason, called primary or de novo MDS[4]. Secondary MDS, also called treatment-related MDS, can develop after previous cancer treatment with chemotherapy or radiation therapy[3][4][5]. Secondary MDS is more common than primary MDS[4].
Environmental factors may play a role. Risk factors include exposure to certain chemicals such as tobacco smoke, pesticides, and benzene, as well as exposure to heavy metals like mercury or lead[5].
Age is the most significant risk factor. About 86% of patients with MDS are older than 60[4]. The condition is uncommon before age 50[4]. Certain genetic conditions can also increase the risk[4].
People with MDS often have changes, called mutations, in certain chromosomes or genes within the MDS cells[4][11]. Common chromosome changes include a deletion or loss of part of chromosomes 5, 7, or 20, complete deletion of chromosome 5 or 7, or an extra copy of chromosome 8[4]. Examples of gene mutations found in MDS cells include SF3B1 and TP53[4].
Signs and symptoms
People with myelodysplastic syndrome might not experience signs and symptoms at first[1][4]. Many people have mild symptoms that slowly get worse over time[4]. The symptoms depend on which type of blood cell is most affected[4].
When symptoms do appear, they often relate to having too few healthy blood cells, a condition called cytopenia[3]. The most common symptom is anemia, which means you have too few red blood cells[2][4]. This can make you feel tired or fatigued and cause shortness of breath[1][4]. You may also notice unusual paleness of your skin[1].
Having too few white blood cells, called leukopenia or neutropenia, makes it harder for your body to fight infections[1][2]. This can lead to frequent infections and fever[1][4].
When you don’t have enough platelets, a condition called thrombocytopenia, you may experience easy or unusual bruising or bleeding that won’t stop[1][2][4]. You might also notice pinpoint-sized red spots just beneath the skin called petechiae, which are caused by bleeding[1].
You should make an appointment with your doctor if you have signs or symptoms that worry you[1].
Diagnosis and testing
If your doctor suspects you have myelodysplastic syndrome, several tests might be used to confirm the diagnosis[7].
Blood tests are typically the first step. Your doctor will order blood tests to determine the number of red cells, white cells, and platelets[7]. These tests also look for unusual changes in the size, shape, and appearance of various blood cells[7]. Many people with MDS have low red blood cell count (anemia), low white blood cell count (neutropenia), or low platelet count (thrombocytopenia), or a combination of these[4].
A bone marrow biopsy and aspiration is the definitive test for diagnosing MDS[7]. During this procedure, a thin needle is used to withdraw a small amount of liquid bone marrow, usually from a spot on the back of your hipbone[7]. A small piece of bone with its marrow is also removed[7].
Blood and bone marrow samples are sent to a laboratory for analysis[7]. Specialized tests can determine the specific characteristics of your cells, which helps doctors identify the type of MDS you have, your outlook, and your treatment options[7]. These tests include examining how the cells look under a microscope, measuring the percentage of blasts, checking for ring sideroblasts, and analyzing chromosomes and genes for abnormalities[2][4].
Treatment approaches
Management of myelodysplastic syndromes is most often intended to slow the disease, ease symptoms, and prevent complications[1][7]. There is no cure for most types of MDS, though some people can be cured through specific treatments[5][7].
Not all patients require treatment initially, as there is no survival benefit with treatment of people who have no symptoms and low-risk disease[3]. Treatment is reserved for patients who are symptomatic, such as those requiring frequent blood transfusions[3].
Your treatment will depend on your symptoms, the type of MDS you have, how quickly your symptoms are expected to get worse, your age, and your general health[13]. If you have low-risk MDS and few symptoms, you’ll usually just have regular check-ups, including blood tests[13]. This approach is called active monitoring or watch and wait[13].
Supportive care includes treatments to prevent or control symptoms. Blood transfusions can increase your number of healthy blood cells[1][13]. Growth factors are medicines that help your body make more blood cells[9][13]. Erythropoietin stimulating agents stimulate the bone marrow to make more red blood cells and can help alleviate anemia[9]. Antibiotics may be needed if you develop infections[13].
Chemotherapy uses medicines to kill cancer cells[13]. It’s one of the main treatments for higher-risk MDS. FDA-approved chemotherapy treatments include hypomethylating agents such as azacitidine and decitabine[9][12]. You might have intensive chemotherapy if you’re preparing for a stem cell transplant, or non-intensive chemotherapy if stronger treatment isn’t suitable for you[13].
Targeted medicines and immunotherapy are treatments that work in specific ways to fight cancer cells. The main targeted medicine used is lenalidomide, which can help with symptoms and reduce the need for blood transfusions[9][13]. It’s primarily used for patients with a specific chromosome abnormality called 5q deletion[9]. Immunosuppressants are medicines that reduce the activity of your immune system and can be used to treat certain types of MDS[13].
A bone marrow transplant, also known as a stem cell transplant, replaces the damaged stem cells in your bone marrow with healthy ones from a donor[1][13]. It can sometimes cure MDS, but it’s not suitable for everyone[13]. It may be recommended if you have lower-risk MDS and other treatments haven’t worked, or if you have higher-risk MDS and you’re in good health apart from your MDS[13].
Outlook and prognosis
The outlook for people with MDS varies widely. Prognosis depends on multiple factors, including the type of cells affected, the number of blasts in the bone marrow or blood, the severity of cytopenias, and the changes present in the chromosomes of the affected cells[3][5].
The disease course is variable[3]. The average survival time following diagnosis is about 2.5 years, though some people live much longer[5]. Patients with certain chromosome changes tend to have different outcomes. For example, patients exhibiting the 5q chromosomal deletion tend to have a more favorable prognosis compared to those with monosomy 7[3].
Some people with MDS may develop acute myeloid leukemia (AML)[1][2]. About 30% of people with MDS will develop AML[4][8]. By medical convention, MDS is reclassified as AML with myelodysplastic features when blood or bone marrow blasts reach or exceed 20%[11].
Many patients die from complications of cytopenias, such as infections or bleeding, before the disease progresses to this stage[11]. The leukemic phase that develops from MDS is less responsive to chemotherapy than AML that develops on its own[11].
Living with myelodysplastic syndrome
Living with MDS can be physically and mentally challenging. Focusing on your well-being through self-care can help you manage symptoms, navigate the trials of treatment, and find balance in everyday life[16].
Protect yourself from infections because MDS may cause a drop in the number of white blood cells that help fight infections[18]. Take steps to keep yourself well by washing your hands often, avoiding people who are sick and crowded places, preparing food safely, and staying up to date on vaccines[18].
Eating a well-balanced diet can help protect your body against MDS and treatment side effects by giving you the nutrients you need for optimal function[16]. A balanced diet typically includes a plant-based diet of fruits, vegetables, and whole grains, low sodium intake, limiting processed foods, avoiding sugary beverages, and reducing intake of refined starches[16]. You may work with your doctor or a dietitian to create a meal plan that works for you[16].
Stay active if your doctor says it’s okay. Exercise can help reduce pain, ease psychological distress, and improve your overall well-being[16][18]. Try to get out each day for a brisk walk, building up over time to 30 to 60 minutes of moderate activity[18].
Managing fatigue is important, as most people with MDS experience lasting tiredness that doesn’t go away with rest[15][18]. Don’t hesitate to let your doctor know if this is a struggle for you[18].
Express how you feel and let yourself experience any emotion that comes up, whether it’s denial, fear, anxiety, or anger[18]. All are normal when dealing with a chronic illness. There’s no wrong way to feel[18].
Ask for help when you need it. Talk to your family and friends about what you’re going through[15][17]. Talking can help increase trust and support between you and them[17].
Connect with others who understand what you’re experiencing. Organizations like the MDS UK Patient Support Group, the MDS Foundation, Blood Cancer UK, and Leukaemia Care offer support services, information, and opportunities to connect with other people affected by blood cancer[15][17].
Taking care of yourself emotionally as well as physically is important[18]. Pay attention to how your body feels, what’s on your mind, and how you’re doing emotionally, as your mental and emotional health will affect your physical health[18].
