Myelodysplastic syndromes (MDS) are conditions that can occur when the blood-forming cells in the bone marrow become abnormal. This leads to low numbers of one or more types of blood cells. MDS is considered a type of cancer.

Normal bone marrow

Bone marrow is found in the middle of certain bones. It is made up of blood-forming cells, fat cells, and supporting tissues. A small fraction of the blood-forming cells are blood stem cells. Stem cells are needed to make new blood cells.

There are 3 main types of blood cells: red blood cells, white blood cells, and platelets.

Red blood cells pick up oxygen in the lungs and carry it to the rest of the body. These cells also bring carbon dioxide back to the lungs. Having too few red blood cells is called anemia. It can make a person feel tired and weak and look pale. Severe anemia can cause shortness of breath.

White blood cells (also known as leukocytes) are important in defending the body against infection. There are different types of white blood cells:

• Granulocytes are white blood cells that have granules that can be seen under the microscope. In the bone marrow, granulocytes develop from young cells called myeloblasts. The most common type of granulocyte is the neutrophil. When the number of neutrophils in the blood is low, the condition is called neutropenia. This can lead to severe infections.
• Monocytes are also important in protecting the body against germs. The cells in the bone marrow that turn into monocytes are called monoblasts.
• Lymphocytes make proteins called antibodies that help the body fight germs. They can also directly kill invading germs. Lymphocytes are not usually abnormal in MDS.

Platelets are thought of as a type of blood cell, but they are actually small pieces of a cell. They start as a large cell in the bone marrow called the megakaryocyte. Pieces of this cell break off and enter the bloodstream as platelets. You need platelets for your blood to clot. They plug up damaged areas of blood vessels caused by cuts or bruises. A shortage of platelets, called thrombocytopenia, can result in abnormal bleeding or bruising.

Myelodysplastic syndromes

In MDS, some of the cells in the bone marrow are abnormal (dysplastic) and have problems making new blood cells. Many of the blood cells formed by these bone marrow cells are defective. Defective cells often die earlier than normal cells, and the body also destroys some abnormal blood cells, leaving the person without enough normal blood cells. Different cell types can be affected, although the most common finding in MDS is a shortage of red blood cells (anemia).

There are several different types of MDS, based on how many types of blood cells are affected and other factors.

In about 1 in 3 patients, MDS can progress to a rapidly growing cancer of bone marrow cells called acute myeloid leukemia (AML). In the past, MDS was sometimes referred to as pre-leukemia or smoldering leukemia. Because most patients do not get leukemia, MDS used to be classified as a disease of low malignant potential. Now that doctors have learned more about MDS, it is considered to be a form of cancer.

Survival statistics are a way for doctors and patients to get a general idea of the outlook (prognosis) for people with a certain type of cancer. They can’t tell you how long you will live, but they may help give you a better understanding about how likely it is that your treatment will be successful. Some people will want to know the survival statistics for their cancer, and some people won’t. If you don’t want to know, you don’t have to.

Median survival is one way to look at outcomes. It is the time after diagnosis at which half the patients in a certain group are still alive, and half have died. This is a middle value – half the patients live longer than this, and half do not live this long.

Survival statistics don't tell the whole story

Survival stats are often based on previous outcomes of large numbers of people who had the disease, but they can’t predict what will happen in any particular person’s case. There are some limitations to remember:

• The numbers below are based on patients diagnosed with a myelodysplastic syndrome (MDS) some time ago. Improvements in treatment since these numbers were gathered may result in a better outlook for people now being diagnosed with MDS.
• These numbers are based on prognostic scores that take into account certain factors, such as the type of MDS, the results of certain blood tests, and whether the abnormal cells have certain chromosome changes. But other factors might also affect a person’s outlook, such as the patient’s age and health, and how well the disease responds to treatment.

Your doctor can tell you how the numbers below apply to you, as he or she is familiar with your particular situation.

Survival statistics for MDS

The following survival statistics are based on the revised International Prognostic Scoring System (IPSS-R) risk groups. It’s important to note that this system is based largely on people who were diagnosed many years ago and who did not get treatments such as chemotherapy for their MDS.

The WHO Prognostic Scoring System (WPSS) risk groups can also be used to predict outcome – both median survival and the chance that the MDS will transform into acute myeloid leukemia (AML) within 5 years. These statistics were published in 2007 based on patients diagnosed between 1982 and 2004.

Remember, these survival statistics are only estimates – they can’t predict what will happen to any individual person. Many other factors can also affect a person’s outlook. We understand that these statistics can be confusing and may lead you to have more questions. Talk to your doctor to better understand your specific situation.

For most types of cancer, the stage of the cancer – a measure of how far it has spread – is one of the most important factors in selecting treatment options and in determining a person’s outlook (prognosis).

But myelodysplastic syndromes (MDS) are diseases of the bone marrow. The outlook for these cancers isn't based on the size of a tumor or whether the cancer has spread. Because of this, doctors use other factors to predict outlook and decide when to treat. Some of these factors have been combined to develop scoring systems.

Revised International Prognostic Scoring System (IPSS-R)

The revised International Prognostic Scoring System (IPSS-R) is based on 5 factors:

• The percentage of blasts (very early forms of blood cells) in the bone marrow
• The type and number of chromosome abnormalities in the cells
• The level of red blood cells (measured as hemoglobin) in the patient's blood
• The level of platelets in the patient's blood
• The level of neutrophils (a type of white blood cell) in the patient's blood

Each factor is given a score, with the lowest scores having the best outlook. Then the scores for the factors are added up to put people with MDS into 5 risk groups:

• Very low risk
• Low risk
• Intermediate risk
• High risk
• Very high risk

These risk groups can be used to help predict a person’s outlook. This can be helpful when trying to determine the best treatment options.

This system has some important limitations. For example, it was developed before many of the current treatments for MDS were available, so it only took into account people who were not treated for their MDS. It also did not include people who have MDS as a result of getting chemotherapy (secondary MDS). But this system can still be helpful and is still widely used.

WHO Prognostic Scoring System (WPSS)

The World Health Organization (WHO) scoring system is based on 3 factors:

• The type of MDS based on the WHO classification (For example, MDS-UD, MDS-RS-SLD, and MDS-del(5q) tend to have the best outlook, whereas MDS-EB tends to have the worst.)
• Chromosome abnormalities (grouped as good, intermediate, or poor)
• Whether or not the patient needs regular blood transfusions

Each factor is given a score, with the lowest scores having the best outlook. Then the scores are added up to put people with MDS into 5 risk groups:

• Very low risk
• Low risk
• Intermediate risk
• High risk
• Very high risk

These risk groups can be used to help predict a person’s outlook, as well as how likely the MDS is to transform into acute myeloid leukemia (AML). This can be helpful when trying to determine the best treatment options. But as with the IPSS-R, this system has some important limitations. For example, it does not include people who have MDS as a result of getting chemotherapy (known as secondary MDS).

Both the IPSS-R and the WPSS can be complex, and different doctors might use different systems. If you have MDS, talk to your doctor about which system they use, which risk group you are in, and what it might mean for your treatment and outlook.

Other prognostic factors

Along with the factors used in these scoring systems, doctors have found other factors that can also help predict a person’s outlook. These include:

• A person’s age
• A person’s performance status (how well they’re able to do normal daily activities)
• The severity of low blood cell counts
• The results of certain blood tests, such as the serum ferritin level
• Certain gene or chromosome changes that are not accounted for in the scoring systems

A main feature of myelodysplastic syndromes (MDS) is that they cause low blood cell counts. Sometimes this is found on blood tests, even before symptoms appear. In other cases, symptoms related to shortages of one or more types of blood cells (cytopenias) are the first sign of MDS:

• Having too few red blood cells (anemia) can lead to feeling tired, dizzy, or weak, as well as shortness of breath and pale skin.
• Not having enough normal white blood cells (leukopenia), especially cells called neutrophils (neutropenia), can lead to frequent or severe infections.
• Having too few blood platelets (thrombocytopenia) can lead to easy bruising and bleeding. Some people have frequent or severe nosebleeds or bleeding from the gums.

Other symptoms can include:

• Weight loss
• Fever
• Bone pain
• Loss of appetite

These symptoms are more likely to be caused by something other than MDS. Still, if you have any of these symptoms, especially if they don’t go away or get worse over time, see your doctor so that the cause can be found and treated, if needed.

Chemotherapy (chemo) is the use of drugs for treating a disease such as cancer. Some chemo drugs can be swallowed as pills, while others are injected by needle into a vein or muscle. These drugs are considered systemic treatment because they enter the bloodstream and reach most areas of the body. This type of treatment is useful for diseases such as myelodysplastic syndrome (MDS) that are not only in one part of the body. The purpose of the chemo is to kill the abnormal stem cells and allow normal ones to grow back.

Hypomethylating agents

These types of chemo drugs affect the way certain genes inside a cell are controlled. These drugs activate some genes that help cell mature. They also kill cells that are dividing rapidly. Examples of this type of drug include:

• Azacitidine (Vidaza)
• Decitabine (Dacogen)

In some MDS patients, using one of these drugs can often improve blood counts (sometimes enough so that blood transfusions aren’t needed), improve quality of life, lower the chance of getting leukemia, and even help a person live longer.

Azacitidine can be injected under the skin or into a vein (IV), often for 7 days in a row each month. Decitabine is often injected into a vein (IV) over 3 hours every 8 hours for 3 days. This is repeated every 6 weeks. Decitabine can also be given by IV over an hour, each day for 5 days in a row, and repeated every 4 weeks.

These drugs can have some of the same side effects as standard chemo drugs (see below), but these side effects are usually milder. A major side effect of these drugs is usually an early drop in blood cell counts, which tends to get better as the drug begins to work. Other side effects can include:

• Fever
• Nausea/vomiting
• Diarrhea or constipation
• Fatigue and weakness

Standard chemotherapy drugs

Standard chemo drugs are less useful for MDS than the hypomethylating agents, so they are not used often. But higher-risk MDS is more likely to progress to acute myeloid leukemia (AML), so some patients with these types of MDS may receive the same chemotherapy treatment as AML patients.

The chemo drug most often used for MDS is called cytarabine (ara-C). It can be given by itself at a low-dose, which can often help control the disease, but doesn’t often put it into remission.

Another option is to give the same, intense type of chemo that is used for younger patients with AML. This means giving cytarabine at a higher dose along with other chemo drugs. This is more often used in younger, healthier patients with higher-risk forms of MDS (like MDS with excess blasts). Some of the chemo drugs that can be combined with cytarabine are:

• Idarubicin
• Daunorubicin

Other chemo drugs might be used as well.

Patients who get the higher dose treatment are more likely to go into remission, but they can also have more severe, even life-threatening side effects, so this treatment is typically given in the hospital. Still, this treatment may be an option for some patients with advanced MDS.

Chemo drugs can cause many side effects. These depend on the type and dose of the drugs that are given and how long they are taken. Common side effects include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Low blood counts

MDS patients already have low blood counts, which often become even worse for a time before they get better.

• Low white blood cell counts lead to an increased risk of serious infections.
• Low platelet counts can lead to problems with easy bruising and can have serious bleeding, including bleeding into the brain or the intestine.
• Low red blood cell counts (or anemia) can lead to fatigue and shortness of breath. In people with heart problems, severe anemia can lead to a heart attack.

If a patient's blood cell counts become too low, they may need supportive therapy (including transfusions) or growth factors to help prevent or treat serious side effects. 

Most side effects from chemo will go away after treatment is finished. Your health care team can often suggest ways to lessen side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting.

Chemo drugs can also affect other organs. For example:

• Idarubicin and daunorubicin can damage the heart, so they are often not given to patients who already have heart problems.
• Cytarabine can affect the brain and cause balance problems, sleepiness, and confusion. This is more common with higher doses.

If serious side effects occur, the chemo treatments may have to be reduced or stopped, at least temporarily. It's important to carefully monitor and adjust drug doses, because some of these side effects can be permanent.

Immune treatments

Immunomodulating drugs (IMiDs)

Lenalidomide (Revlimid) belongs to a class of drugs known as immunomodulating drugs (IMiDs). It seems to work well in low-grade MDS, often eliminating the need for blood transfusions, at least for a time. The drug seems to work best in people whose MDS cells are missing a part of chromosome 5 (MDS-del(5q)). But it can also help some MDS patients that do not have this abnormal chromosome.

Side effects can include:

• Lowered blood counts (most often the white cell count and platelet count)
• Diarrhea or constipation
• Fatigue and weakness

This drug can also increase the risk of serious blood clots that start in the veins in the legs (called a deep vein thrombosis, or DVT). Sometimes, part of a DVT can break off and travel to the lungs (called a pulmonary embolus or PE), where it can cause breathing problems or even death.

This drug might also cause serious birth defects if given to pregnant women. Because of this, it's only available through a special program by the drug company.

Immune system suppression

Drugs that suppress the immune system can help some patients with lower-risk MDS. These drugs are most helpful for people with low numbers of cells in the bone marrow (called hypocellular bone marrow).

Anti-thymocyte globulin (ATG) is an antibody against a type of white blood cell called the T-lymphocyte, which helps control immune reactions. For some patients with MDS, T-lymphocytes interfere with normal blood cell production, so ATG can be helpful. ATG is given as an infusion through a vein. It must be given in the hospital because it can sometimes cause severe allergic reactions leading to low blood pressure and problems breathing.

Cyclosporine is another drug that can suppress the immune system. It can be used along with ATG to help some patients with MDS. Side effects of cyclosporine can include loss of appetite and kidney damage.

It is important to have open and honest discussions with your cancer care team about your myelodysplastic syndrome (MDS). You should feel free to ask any question, no matter how minor it might seem. For instance, consider these questions:

When you’re told you have MDS

• How sure are you about the diagnosis of MDS?
• Can you explain what MDS is? How is it different from leukemia?
• Do I need any other tests before we can decide on treatment?
• Do I need to see any other types of doctors?
• What type of myelodysplastic syndrome do I have?
• Which risk group does my MDS fall into? How might this affect my prognosis and treatment options?
• Are there other factors that could affect my outlook or treatment options?
• If I’m concerned about the costs and insurance coverage for my diagnosis and treatment, who can help me?

When deciding on a treatment plan

• How much experience do you have treating MDS?
• What treatment choices do I have? Do we need to treat the MDS right away?
• Which treatment, if any, do you recommend, and why?
• Should I get a second opinion before starting treatment? Can you suggest a doctor or cancer center?
• What should I do to be ready for treatment?
• How long will treatment last? What will it be like? Where will it be done?
• What are the risks or side effects of the treatments that you recommend? How long are they likely to last?
• Will treatment affect my daily activities?
• What is the outlook for my survival?

During and after treatment

Once treatment begins, you’ll need to know what to expect and what to look for. Not all of these questions may apply to you, but getting answers to the ones that do may be helpful.

• How will we know if the treatment is working?
• What type of follow-up will I need during and after treatment?
• Is there anything I can do to help manage side effects?
• What symptoms or side effects should I tell you about right away?
• How can I reach you on nights, holidays, or weekends?
• Do I need to change what I eat during treatment?
• Are there any limits on what I can do? 
• Should I exercise? What should I do, and how often?
• Can you suggest a mental health professional I can see if I start to feel overwhelmed, depressed, or distressed?
• What would my options be if the treatment isn’t working?
• Where can I find more information and support?

Along with these sample questions, be sure to write down any others you want to ask. For instance, you might want information about recovery times so that you can plan your work or activity schedule. Or you might want to ask about clinical trials that might be right for you.

Keep in mind that doctors aren’t the only ones who can give you information. Other health care professionals, such as nurses and social workers, can answer some of your questions. To learn more about speaking with your health care team, see Talking With Your Doctor.

The number of people diagnosed with myelodysplastic syndromes (MDS) in the United States each year is not known for sure. Some estimates have put this number at about 10,000, while other estimates have been much higher.

MDS is uncommon before age 50, and the risk increases as a person gets older. It is most commonly diagnosed in people in their 70s. The number of new cases diagnosed each year is likely increasing as the average age of the US population increases.

Some cases of myelodysplastic syndrome (MDS) are linked to known risk factors, but most often, the cause is unknown.

Scientists have made great progress in understanding how certain changes in the DNA in bone marrow cells may cause MDS to develop. DNA is the chemical that makes up our genes, which control how our cells function. We usually look like our parents because they are the source of our DNA. But DNA affects more than the way we look.

Some genes control when our cells grow, divide into new cells, and die: 

• Certain genes that help cells grow, divide, and stay alive are called oncogenes. 
• Genes that help keep cell division under control, or cause cells to die at the right time are called tumor suppressor genes. 

Cancers can be caused by gene mutations (defects) that turn on oncogenes or turn off tumor suppressor genes.

Usually mutations in several different genes inside bone marrow cells are needed before a person develops MDS. Some of the mutations most often seen in MDS cells include those in the DNMT3A, TET2, ASXL1, TP53, RUNX1, SRSF2, and SF3B1 genes. Some of these gene changes can be inherited from a parent, but more often they happen during a person’s lifetime.

Inherited gene changes

Researchers have found the gene changes that cause some rare inherited syndromes (like familial platelet disorder with a propensity to myeloid malignancy) linked to an increased risk of developing MDS. This syndrome is caused by inherited changes in the RUNX1 gene. Normally, this gene helps control the development of blood cells. Changes in this gene can lead to blood cells not maturing like they normally would, which can increase the risk of developing MDS.

Gene changes acquired during a person’s lifetime

Often, it’s not known why people without inherited syndromes develop MDS. 

Some outside exposures can lead to MDS by damaging the DNA inside bone marrow cells. For example, tobacco smoke contains chemicals that can damage genes. Exposure to radiation or certain chemicals such as benzene or some chemotherapy drugs can also cause mutations that lead to MDS.

But sometimes the gene changes that lead to MDS seem to occur for no apparent reason. Many of these gene changes are probably just random events that sometimes happen inside a cell, without having an outside cause. 

Gene changes inside cells can build up over a person’s lifetime, which might help explain why MDS largely affects older people.

There is no sure way to prevent myelodysplastic syndromes (MDS). But there are things you can do that might lower your risk.

Not smoking

Since smoking is linked to an increased risk of MDS, not smoking can lower the risk. Of course, nonsmokers are also less likely than smokers to develop many other types of cancers, as well as heart disease, stroke, and other diseases.

Avoiding exposure to radiation or certain chemicals

Avoiding known cancer-causing industrial chemicals, such as benzene, might lower your risk of developing MDS. 

Treating cancer with radiation and certain chemotherapy drugs can increase the risk of MDS. Doctors are studying ways to limit the risk of MDS in patients who get these treatments. For some cancers, doctors may try to avoid using the chemotherapy drugs that are more likely to lead to MDS. Some people, however, may need these specific drugs. Often, the obvious benefits of treating life-threatening cancers with chemo and radiation therapy must be balanced against the small chance of developing MDS several years later.

At this time, there are no widely recommended tests to screen for myelodysplastic syndromes (MDS). (Screening is testing for cancer in people without any symptoms.)

MDS is sometimes found when a person sees a doctor because of signs or symptoms they are having. These signs and symptoms often do not show up in the early stages of MDS. But sometimes MDS is found before it causes symptoms because of an abnormal result on a blood test that was done as part of a routine exam or for some other health reason. MDS that is found early does not always need to be treated right away, but it should be watched closely for signs that it's progressing.

For some people who are known to be at increased risk, such as people with certain inherited syndromes or people who have received certain chemotherapy drugs, doctors might recommend close follow-up with blood tests or other exams or tests to look for possible early signs of MDS.

Since myelodysplastic syndromes (MDS) are very hard to cure, most people with MDS never actually complete treatment. People may go through a series of treatments with rest in between. Some people might choose to stop active treatment in favor of supportive care. Learning to live with cancer that does not go away can be difficult and very stressful. See Managing Cancer as a Chronic Illness for more about this.

Follow-up care

Whether or not you're being actively treated for MDS, your doctors will still want to watch you closely, so it's very important to go to all follow-up appointments.

Exams and tests

During follow-up visits, your doctors will ask about symptoms, examine you, and may order blood tests. They will continue to watch for signs of infection or progression to leukemia, as well as for short-term and long-term side effects of treatment. This is a good time for you to ask your health care team any questions you need answered and to discuss any concerns you might have.

Almost any cancer treatment can have side effects. Some may not last long, but others can be permanent. Don’t hesitate to tell your care team about any symptoms or side effects that bother you so they can help you manage them.

Keeping health insurance and copies of your medical records

It’s very important to keep health insurance. With a chronic disease like MDS, your treatment may never really be over. You don’t want to have to worry about paying for it. Many people have been bankrupted by medical costs.

At some point after your treatment, you might find yourself seeing a new doctor who doesn’t know about your medical history. It’s important to keep copies of your medical records to give your new doctor the details of your diagnosis and treatment. Learn more in Keeping Copies of Important Medical Records.

Can I lower my risk of the MDS progressing?

If you have MDS, you probably want to know if there are things you can do to reduce your risk of it progressing, such as exercising, eating a certain type of diet, or taking nutritional supplements. At this time, not enough is known about MDS to say for sure if there are things you can do will help. 

Adopting healthy behaviors such as not smoking, eating well, getting regular physical activity, and staying at a healthy weight may help, but no one knows for sure. However, we do know that these types of changes can have many other positive effects on your health, including helping you feel better.

About dietary supplements

So far, no dietary supplements (including vitamins, minerals, and herbal products) have been shown to clearly help lower the risk of MDS progressing. This doesn’t mean that no supplements will help, but it’s important to know that none have been proven to do so.

Dietary supplements are not regulated like medicines in the United States – they don’t have to be proven effective (or even safe) before being sold, although there are limits on what they’re allowed to claim they can do. If you’re thinking about taking any type of nutritional supplement, talk to your health care team. They can help you decide which ones you can use safely while avoiding those that might be harmful.

Getting emotional support

Some amount of feeling depressed, anxious, or worried is normal when MDS is a part of your life. Some people are affected more than others. But everyone can benefit from help and support from other people, whether friends and family, religious groups, support groups, professional counselors, or others. To learn more about this, see Coping With Cancer.