Myelodysplastic syndromes (MDS) are a group of blood cancers in which your bone marrow doesn’t make enough healthy blood cells. Instead, many of the cells made in your bone marrow are irregular.

These irregular cells crowd out healthy blood cells, including red blood cells (RBCs), and reduce their numbers. This can lead to anemia.

Anemia caused by MDS must be carefully managed because it can cause potentially serious complications. In this article, we’ll cover the symptoms of anemia in MDS, why it happens, and how it’s treated.

If you have anemia with MDS, you might experience symptoms such as:

Other MDS symptoms

Other MDS symptoms are associated with low counts of other types of blood cells, such as white blood cells (WBCs) and platelets.

Low WBC counts lower your resistance to infections. Because of this, you may notice that you develop frequent infections that are often severe.

Platelets help your blood form clots. When your platelet levels are too low, you might have symptoms such as:

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In MDS, many of the blood cells made in your bone marrow are irregular (dysplastic). These irregular blood cells don’t function properly and often die much earlier than healthy blood cells.

MDS are also associated with high levels of immature blood cells called blasts. People without MDS may have a small number of blasts, but blasts can make up 5–19% of cells in the bone marrow of people with MDS.

In MDS, irregular and immature cells crowd out healthy blood cells, lowering their numbers. When this affects RBCs, it can cause anemia. According to the American Cancer Society, anemia is the most common finding in MDS.

MDS develop due to genetic or chromosomal changes in stem cells that usually go on to become blood cells. These changes can be either inherited or acquired during your lifetime.

The genetic or chromosomal changes in MDS stop the stem cells in your bone marrow from developing as they should. A 2022 study explains how one of the more common gene mutations in MDS can lead to severe forms of anemia.

Many people with MDS will have anemia at the time of diagnosis or develop it at some point.

If you’ve received an MDS diagnosis and you begin having symptoms of anemia, contact your doctor to discuss them. Your doctor will order blood tests to check your RBC count.

Your doctor may also want to check your levels of:

  • hemoglobin, a protein that carries oxygen in your RBCs
  • reticulocytes, immature cells that eventually become RBCs
  • erythropoietin, a hormone that stimulates RBC production

Depending on your test results, your doctor will recommend treatments to help relieve anemia symptoms and improve your RBC count. They will also go over the benefits, drawbacks, and side effects of each treatment and listen to any questions or concerns you may have.

Follow your treatment plan carefully. Many people develop resistance to some of the drugs that are prescribed for anemia in MDS.

Let your doctor know if your medications don’t seem to work to manage your symptoms. They can evaluate your condition and recommend other treatment options that may be effective.

Anemia due to MDS is treated with supportive care, which doesn’t directly treat the cancer but helps ease symptoms and improve blood counts.

Possible treatments for MDS and anemia include:

  • Erythropoiesis-stimulating agents (ESAs): An injection of factors that promote RBC production can help stimulate your bone marrow to make more RBCs. Examples include epoetin alpha (Epogen, Procrit) and darbepoetin alfa (Aranesp).
  • Blood transfusions: During a blood transfusion, you’ll receive healthy blood from a donor with a matching blood type. However, frequent blood transfusions can cause iron levels to rise, which can affect organ function. In that case, you may receive iron chelation therapy, which involves drugs that bind to excess iron and allow your body to properly remove it.
  • Lenalidomide (REVLIMID): Lenalidomide is an immunomodulator that helps your body target irregular bone marrow cells and produce healthy ones. Some people with MDS have a deletion in the long arm of chromosome 5, which is associated with acute myeloid leukemia (AML). People with lower risk MDS who have this deletion have responded well to treatment with lenalidomide.
  • Luspatercept (Reblozyl): Luspatercept is an injectable biologic medication approved for use for MDS anemia if the above treatments aren’t effective. It stimulates RBCs to mature. In August 2023, the Food and Drug Administration (FDA) approved luspatercept as a first-line treatment for anemia in people with low to intermediate risk MDS who have not had ESAs.
  • Hypomethylating agents: DNA methylation is when small chemical groups (methyls) attach to a DNA molecule. These groups don’t change the structure of the DNA but instead affect its activity. Hypomethylating agents aim to reprogram or adjust DNA gene expression to stop cancer cell growth and spread.
    • IV decitabine (Dacogen) and azacitidine (Vidaza) are lower intensity chemotherapy drugs that are FDA-approved to treat MDS. They are often referred to as DAC and AZA. Through different processes, both can result in the reactivation of tumor-suppressor genes that can help stop cancer cell growth.
    • An oral combination of decitabine and cedazuridine (C-DEC) is also FDA-approved to treat MDS.
    • Azacitidine (Onureg) and venetoclax (Venclexta) were recently granted breakthrough therapy status by the FDA to treat intermediate to high risk MDS. This means the clinical trials are prioritized. Currently, this regimen is not used outside trials.
  • Allogeneic stem cell transplantation (allo-SCT): This is the only curative treatment for MDS and is usually used only in younger people with MDS since it has a higher rate of complications. Allo-SCT treatment involves receiving a high dose of chemotherapy and then an infusion of blood-forming stem cells from a donor. A potentially serious complication of this is graft vs. host disease.

Medications can help some people reach transfusion independence, which means they no longer need to receive regular blood transfusions.

It’s important to treat anemia in MDS. Without treatment, anemia can cause cardiovascular complications such as heart failure. This is because low levels of RBCs mean your heart has to work harder to supply your body with oxygen.

But treating anemia in MDS can be challenging. A 2021 review notes that while many people initially respond to ESAs, many will become resistant to this treatment and need blood transfusions.

Blood transfusions can help treat anemia but can also lead to iron buildup in your body. This can require further treatment with iron chelation therapy as well as higher healthcare costs and a lower quality of life.

RBC levels are one of the factors used to predict the outlook for MDS. The most commonly used prognostic system for MDS is the Revised International Prognostic Scoring System (IPSS-R), which looks at:

  • the levels of RBCs, WBCs, and platelets in your blood
  • the percentage of blasts in your bone marrow
  • whether any chromosome changes are present, and if so, which types

Once all factors are scored, a risk group is assigned. These groups assess the risk of progression to AML, as well as overall survival time. Risk groups can help your doctor decide what initial therapy to use.

The table below shows the median survival time for each of the IPSS-R risk groups, according to the American Cancer Society.

IPSS-R risk groupMedian survival time
very low8.8 years
low5.3 years
intermediate3 years
high1.6 years
very high0.8 years

However, these numbers represent people who received a diagnosis years ago and often didn’t have access to chemotherapy. Additionally, each person is different, and disease progression is not always easy to predict.

Anemia is a common occurrence in MDS. It happens when irregular and immature blood cells crowd out healthy RBCs, lowering their numbers. Symptoms of anemia can include fatigue, weakness, and shortness of breath.

Anemia due to MDS is treated with treatments such as ESAs and blood transfusions. These treatments can ease anemia symptoms and increase levels of healthy RBCs in your body.

Serious complications can happen when anemia isn’t treated. Make an appointment with your doctor if you have MDS and notice anemia symptoms or if your current treatment plan isn’t effectively managing your anemia.