What Is Acute Myeloid Leukemia?
Acute myeloid leukemia (AML) is a type of blood cancer that starts in your bone marrow, which is the soft inner part of your bones where all your blood cells are made. AML usually begins in cells that turn into white blood cells but can also start in other blood-forming cells. When bone marrow cells don't grow properly, immature cells called blasts build up in your bone marrow and spill into your blood.
You may hear other names for acute myeloid leukemia, including:
- Acute myelocytic leukemia
- Acute myelogenous leukemia
- Acute granulocytic leukemia
- Acute nonlymphocytic leukemia
AML is rare; only about 1% of all cancers are AML. It usually affects people who are older than 45 years, and it's more common in men and people assigned male at birth.
There are several types of AML depending on the kind of gene mutations you have, how developed the leukemia cells are when you're diagnosed, and how different they are from normal cells. For instance, one type is called acute promyelocytic leukemia (APL), which occurs when genes from chromosomes 15 and 17 switch places, creating an abnormal gene. This gene prevents a type of white blood cell called a promyelocyte from fully developing. People with APL respond better to treatment than people with other types of AML.
Since AML doesn't form solid tumors, staging is based on:
- Your age; people younger than age 60 tend to do better than those older than 60
- The number of white blood cells you have at diagnosis; people with a white blood cell count under 100,000 per milliliter of blood tend to do better
- What types of genetic changes you have in your leukemia cells
- If you had a blood disorder leading to AML; people tend to do better if they didn't have myelodysplastic syndrome before developing AML
- If you had treatment for another cancer that led to AML
- If you had an infection when you were diagnosed
- If leukemia cells were found in your brain and spinal cord when you were diagnosed
- How well and how quickly you respond to treatment for AML
It's important to get treatment quickly when you have AML, as it can spread quickly to your blood and other parts of your body, such as your:
- Lymph nodes
- Liver
- Spleen
- Brain and spinal cord
- Testicles
Read on to learn a bit more about the causes, risk factors, and potential treatment options for AML.
AML Causes and Risk Factors
Acute myeloid leukemia (AML) is caused by mutations in genes in certain cells of your bone marrow. This is the inner part of your bones that produces blood cells, including red blood cells, white blood cells, and platelets.
When you have AML, your bone marrow makes abnormal white blood cells called myeloid blasts or myeloblasts. White blood cells are an important part of your immune system and help keep you from getting sick. Several different types of white blood cells perform different roles in your immune system. Myeloid blasts typically have the potential to grow into all these different types of white blood cells.
But when you have AML, the myeloid blasts don't get all the instructions they need to develop into the different types of white blood cells. So, instead of moving into your blood as mature white blood cells, they build up in your bone marrow.
Because these abnormal myeloid blasts keep growing and multiplying and don't die off, they crowd out the other kinds of cells in your bone marrow that make red blood cells and platelets. This means your bone marrow may not be able to make all the blood cells you need to be healthy. And these abnormal myeloid blasts can flow into your bloodstream. Once there, they can travel all over your body.
AML risk factors
Experts don't know exactly why people get the mutations that cause AML. But some things may make you more likely to get it. These include:
Age over 45 years. Most people who are diagnosed with AML are over 45 years of age. About half are older than 65, with a median age of 68 at first diagnosis.
Having certain demographic characteristics. Experts don't know why, but leukemia in general is more common in men and people assigned male at birth than in women and people assigned female at birth. It's also more commonly diagnosed in White people of non-Hispanic descent than other ethnicities.
Smoking tobacco products. Cancer-causing chemicals you inhale when smoking don't stay in your mouth, throat, and lungs. They're absorbed by your lungs where they move into your bloodstream and travel all over your body.
Long-term exposure to cancer-causing chemicals, such as benzene and formaldehyde. Benzene is one of the most widely used industrial chemicals in the U.S. It's a solvent used in the rubber industry, oil refineries, chemical plants, shoe manufacturing, and industries that use a lot of gasoline. It's present in cigarette smoke, gasoline, car exhaust, as well as some glues, cleaning products, detergents, art supplies, and paints. Studies show that exposure to benzene may increase your risk for AML, but this is usually when you have long-term exposure at work.
Formaldehyde is used as an industrial disinfectant and as a preservative in funeral homes and medical labs. It's also used to make building materials and some household products, such as particleboard, plywood, fiberboard, glue, permanent-pressed fabrics, paper coatings, and insulation. Some studies show that exposure to formaldehyde at your job may increase your risk for AML.
Treatment with certain chemotherapy medicines. Chemotherapy drugs, such as alkylating agents and topoisomerase II inhibitors, have been linked to AML risk years after your treatment. Alkylating agents keep cells from multiplying and are used in treating many different types of cancers, including lung, breast, and ovarian cancers, as well as leukemia, lymphoma, Hodgkin disease, multiple myeloma, and sarcoma. Alkylating agents include busulfan, carboplatin, carmustine, chlorambucil, cisplatin, cyclophosphamide, mechlorethamine, and melphalan. With alkylating agents, you may first develop a myelodysplastic syndrome, which may then develop into AML.
Topoisomerase II inhibitors block certain enzymes that cancer cells need to multiply. It's used to treat some leukemias, lung, ovarian, gastrointestinal, colorectal, and pancreatic cancers. Topoisomerase II inhibitors include doxorubicin, epirubicin, etoposide, mitoxantrone, and teniposide. With topoisomerase II inhibitors, you usually develop AML without getting myelodysplastic syndrome first.
Exposure to high doses of radiation. People who are exposed to low levels of radiation, such as from X-rays or CT scans, especially at a very young age, may have an increased risk of leukemia. It's challenging to determine how much extra risk this gives you since it depends on what type of radiation you had, for how long, if it's repeated exposure, and how young you were.
People who have had high-dose radiation exposure, such as survivors of nuclear reactor accidents, have a much higher risk of developing acute leukemia than people without this exposure.
Having certain blood conditions. Chronic myeloproliferative disorders, such as polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis, may increase your risk for AML, especially if you have chemotherapy or radiation therapy to treat them. You also have an increased AML risk if you have myelodysplastic syndrome (MDS). MDS may eventually change over time to AML, and such cases can be very challenging to treat.
Having certain genetic syndromes. When you have a genetic syndrome, you're born with gene mutations. Some of these syndromes can raise your risk of AML. These include:
- Fanconi anemia
- Bloom syndrome
- Ataxia-telangiectasia
- Diamond-Blackfan anemia
- Shwachan-Diamond syndrome
- Li-Fraumeni syndrome
- Neurofibromatosis type 1
- Severe congenital neutropenia (Kostmann syndrome)
- Down syndrome
- Trisomy 8
Having a family history of AML. Having a parent, brother, or sister with AML increases your risk of getting it. If you're an identical twin and your twin developed AML before you were 1 year old, you too have a high risk of developing AML.
How common is acute myeloid leukemia?
AML is a rare cancer, making up only about 1% of all cancers. In the U.S., a little over 20,000 people per year are diagnosed with AML. This is about a third of all leukemia diagnoses.
AML Symptoms
People with AML may develop general or nonspecific symptoms. These symptoms are nonspecific because they can be caused by several other conditions. Such symptoms include:
- Weight loss
- Fatigue
- Fever
- Night sweats
- Loss of appetite
When you have AML, the abnormal myeloid blast cells can crowd out the other cells in your bone marrow that make blood cells. This can prevent your bone marrow from making enough red blood cells, white blood cells, and platelets to feel healthy. Your doctor will be able to see shortages of blood cells on blood tests, but you may also have symptoms depending on which blood cells you're short of.
Symptoms of low red blood cell counts (anemia) include:
- Fatigue (extreme tiredness)
- Weakness
- Feeling cold
- Feeling lightheaded or dizzy
- Headaches
- Pale skin
- Shortness of breath
Symptoms of low white blood cell counts include:
- Infections that don't seem to go away
- Back-to-back infections
- Fever
Symptoms of low platelet counts include:
- Bruises on your skin, including small red or purple spots called petechiae
- Bleeding from your gums
- Frequent or severe nosebleeds
- Bleeding excessively
- Heavy bleeding during your menstrual period
If you have a type of AML called acute promyelocytic leukemia (APL), you may have problems with bleeding or blood clotting. For instance, you may have a nosebleed or cut that won't stop bleeding. You may also develop deep vein thrombosis (DVT), which is when you have a blood clot in one of your deep veins; it's usually in your leg but may also form in your groin or arm. This will cause swelling, redness, pain, and warmth in your skin near the blood clot. Or, you may develop pulmonary embolism (PE), which is when you have a blood clot in your lung. This may cause shortness of breath and chest pain.
Symptoms caused by high levels of myeloid blasts
When you have AML, your bone marrow makes abnormal cells called myeloid blasts. These cells are bigger than normal white blood cells, so they have trouble moving through your smaller blood vessels. If you have high levels of these myeloid blasts, they may block the flow in small blood vessels. This may make it hard for your red blood cells to deliver oxygen to all your tissues. This is called leukostasis, and it's a rare symptom of AML. You may have symptoms that look a lot like those of stroke, such as:
- Headache
- Weakness on one side of your body
- Slurred speech
- Confusion
- Drowsiness or excessive sleepiness
- Shortness of breath (if the small vessels in your lungs are affected)
- Blurry vision or even vision loss (if the small vessels in your eyes are affected)
Leukostasis is a medical emergency. If you have these symptoms, you need to get to the doctor for treatment right away.
Bone or joint pain. If you have a buildup of myeloid blasts in your joints, you may have bone and joint pain.
Swelling in your liver (hepatomegaly) and spleen (splenomegaly). Myeloid blasts may build up in your liver and spleen, causing them to swell. You may notice bloating or swelling in your belly right below your rib cage. Your doctor will be able to feel your swollen liver and spleen when they examine your belly.
Symptoms from the spread of leukemia cells
- If they spread to your skin, you may get lumps or spots that look like a rash.
- If they spread to your gums, your gums may swell, hurt, and bleed.
- If they spread to your brain or spinal cord, you may have headaches, weakness, seizures, vomiting, trouble balancing, facial numbness, or blurred vision.
- If they spread to your lymph nodes, you may have swelling in any of your lymph nodes, but especially in your neck, groin, armpits, and above your collarbone.
AML Diagnosis
Your doctor will start by asking about your medical history, especially your symptoms, how long you've had them, and possible risk factors for AML. They’ll do a physical exam to look for signs of bleeding, bruising, infection, and swelling in your liver and spleen.
To confirm the diagnosis, learn more about the type of AML you have, and learn more about what's happening in your body, your doctor will order tests, such as:
Blood and other laboratory tests
The types of blood tests your doctor may use include:
- A complete blood count (CBC). It shows how many of each type of blood cell you have.
- A differential count of the types of white blood cells you have.
- A peripheral blood smear. A technician or pathologist looks at a sample of your blood under the microscope. They may be able to see changes in the numbers and appearance of your blood cells which can help them diagnose you. For instance, if your blood is at least 20% myeloid blasts, you likely have AML, though your doctor will have to do other tests to confirm it.
- Blood chemistry and coagulation tests. The results of these tests will help your doctor figure out if you have liver or kidney issues, abnormal levels of certain minerals, or trouble with blood clotting.
- Looking at bone marrow and cerebrospinal fluid (CSF) tissue samples under the microscope for signs of myeloid blasts.
- Staining cells with special dyes (called immunohistochemistry) that can show what kind of cells they are. These tests are called immunophenotyping tests, and they use a special machine called a flow cytometer to help sort the cells into their different types. These tests tell your doctor what type of leukemia cells you have and how many of them you have.
- Chromosome and gene tests to look for the chromosome changes that are characteristic of AML. The lab that tests your samples may use several techniques, such as karyotyping, fluorescent in situ hybridization (FISH), and polymerase chain reaction (PCR) to examine your chromosomes and genes.
- Biomarker testing. It can help your doctor learn more about the specific type of leukemia you have and whether certain treatments are likely to work for you.
Imaging tests
Leukemia is a blood cancer that doesn't form solid tumors in your body. So, imaging tests such as X-rays, CT scans, MRIs, and ultrasounds won't help your doctor diagnose the cancer. But they can help your doctor figure out if you're having other problems, such as swelling in your spleen and liver or an infection in your lungs. Imaging can also show if the cancer has spread outside your bone marrow and blood.
AML Treatment
Different types of treatment are available for AML, including chemotherapy, radiation therapy, stem cell transplant, targeted therapy, and supportive therapy. Your cancer care team will work with you to decide your best treatment plan. This will depend on many different factors, such as:
- Your general health
- The phase of your cancer
- If cancer has spread to other organs
- Your goals for treatment
- Your personal preferences
In general, treatment of AML occurs in two phases:
Remission induction therapy. This aims to kill the leukemia cells in your blood and bone marrow, allowing you to go into remission. Remission means you have little or no signs of cancer.
Post-remission or remission continuation therapy (called consolidation therapy in the past). After you have achieved remission, this therapy aims to kill any remaining leukemia cells so the cancer doesn’t come back (relapse).
In some cases, you may not be able to have post-remission therapy. In that case, your doctor may recommend maintenance therapy, which uses lower doses of chemotherapy to maintain your remission. You may continue on maintenance therapy for months or years.
During treatment, you will be closely monitored for myelosuppression, which is a side effect of chemotherapy where your body doesn't make enough blood cells to keep you healthy. You may get supportive therapy for this, such as red blood cell and platelet transfusions or antibiotics and antifungals to prevent infections.
In either phase, you may have one or more types of treatment, such as:
Chemotherapy
It uses certain medicines that can kill cancer cells or stop them from multiplying. You might take these medicines by mouth, through an IV, or via a shot into another part of your body, depending on the type of AML you have and whether it has spread to your brain and spinal cord.
You will usually get a combination of different types of chemotherapy medicines or chemotherapy medicines plus a targeted therapy. If the cancer has spread to your brain and spinal cord, you may also get intrathecal (pronounced in-truh-thee-kul) chemotherapy. Intrathecal therapy is when chemotherapy drugs are injected into the space between the layers of tissue that cover your brain and spinal cord.
Chemotherapy drugs typically used for AML include:
- Azacitidine
- Cytarabine
- Daunorubicin
- Daunorubicin plus cytarabine
- Decitabine
- Idarubicin
- Midostaurin
- Mitoxantrone
Radiation therapy
Radiation therapy uses high-energy X-rays or other types of radiation to kill cancer cells or stop them from growing. You may have external beam radiation therapy, where the radiation is concentrated on just the part of your body with cancer. If AML recurs and you're planning on having a stem cell transplant, you may get total-body irradiation, where a large machine directs radiation toward your whole body.
Stem cell transplant
When you have had an AML recurrence or are at high risk for it, you and your doctor may decide to replace the abnormal immature blood cells (stem cells) in your bone marrow with either your own or those from a donor. These cells will restore your bone marrow so you can make the blood cells you need.
Targeted therapy
Targeted therapy is a treatment that targets specific chemicals cancer cells make that help them grow, divide, and spread. To help choose these treatments, your doctor can use biomarker testing when you're being worked up after your diagnosis. Or, you may get targeted therapy if you aren't healthy enough or don't want to take intense chemotherapy medicines.
Some common targeted therapies used for AML treatment include:
- Enasidenib
- Gemtuzumab ozogamicin
- Gilteritinib
- Ivosidenib
- Quizartinib
- Venetoclax
Other medications
If you have a type of AML called acute promyelocytic leukemia (APL), you may also get arsenic trioxide (Trisenox) and all-trans retinoic acid (ATRA).
Choosing to stop AML treatment
Sometimes, your cancer comes back after treatment or your treatment stops working. In that case, you may consider getting a second opinion or enrolling in a clinical trial. Clinical trials are a good way to try new medicine that isn't available to everyone yet. Your doctor can tell you if one of these studies might be a good fit for you. Before you sign up, ask for information on what’s involved and what your potential risks and benefits are.
You may also decide to stop treatment altogether and enter hospice care. In hospice, the goal is to help you manage your symptoms and maintain a good quality of life.
Regardless of whether you choose to continue with treatment or not, you will receive palliative care, which helps ease your symptoms and side effects, such as nausea and pain. That way you can focus on living well and feeling your best.
Acute Myeloid Leukemia Complications
You may have complications from AML or as a side effect of treatment. Complications can include:
A weakened immune system
This is usually a result of treatment. You may be more prone to developing infections, and any infections you develop may be more serious than before treatment. You'll need to take more care to avoid infections. If you do develop one, you need to get treatment right away to keep it from getting worse. Pay extra attention to the signs and symptoms of an infection, such as fever, sore throat, headaches, muscle aches, fatigue, feeling out-of-breath, and pain when you pee.
Depending on your circumstances, your doctor may:
- Prescribe antibiotics that you take regularly to prevent bacterial infections
- Ask you to be extra careful about your personal and dental hygiene
- Ask you to avoid contact with anyone who has an infection, even infections you were previously immune to, such as chickenpox or measles
- Ask you to keep up-to-date with all your vaccines but avoid vaccines that have "live" viruses, such as shingles and measles, mumps, and rubella (MMR)
Bleeding
One of the symptoms of AML is bleeding and bruising more easily because you don't have enough platelets in your blood to stop it. The more advanced your cancer, the more likely you are to have this complication. Any type of internal bleeding (hemorrhage) is a medical emergency. If you have any symptoms of internal hemorrhage, call 911 and get to the ER right away. These symptoms may include:
- Severe headache, stiff neck, vomiting, and confusion if you have bleeding inside your skull (intracranial hemorrhage)
- Coughing up blood, trouble breathing, or a bluish skin tone if you have bleeding in your lungs (pulmonary hemorrhage)
- Throwing up blood or dark, black, tar-like poop if you have bleeding in your stomach (gastrointestinal hemorrhage)
Infertility
Most of the treatments used for AML can cause infertility. It can be temporary or permanent. You are especially at risk for infertility if you had high-dose chemotherapy or radiation therapy before a stem cell transplant. Make sure you talk to your doctor about your risk of infertility before treatment. If it's important to you, they may suggest you freeze your eggs or sperm before you start your treatment.
Living With Acute Myeloid Leukemia
Cancer treatment can be challenging. But there are several things you can do to help support yourself, including:
- Keep up with all your follow-up exams and tests.
- Consider joining a support group or going to see a counselor.
- If your appetite is low, ask your doctor about consulting a nutritionist to help you get the most nutrients from the foods you eat.
- If you're having trouble with side effects, talk to your doctor about your palliative care options.
- Try to stay as active as possible, which can help you manage your stress levels and stay healthy.
- Get plenty of good quality sleep. Talk to your doctor if you're having trouble sleeping.
Takeaways
Acute myeloid leukemia (AML) is a cancer that starts in the cells of your bone marrow that make different types of blood cells. It usually starts in a precursor cell to one type of white blood cell. Many of the symptoms of AML are nonspecific, which means they can be caused by several different conditions. These symptoms include loss of appetite, weight loss, fatigue, fever, night sweats, easy bruising, and bleeding. Treatment is usually with a high-dose combination chemotherapy regimen, which may also include targeted therapy. Your cancer care team will help you choose the right treatment based on your specific situation.
Acute Myeloid Leukemia FAQs
Is AML cancer curable?
Generally speaking, AML is not curable. The only potential cure for AML is an allogeneic stem cell transplant. That is when you have the stem cells in your bone marrow replaced with those from a donor. In many cases, your doctor will only recommend testing for an allogeneic stem cell transplant when you've been treated for AML and it has come back within 12 months. Unfortunately, not everyone is a candidate for stem cell transplant. It's a very intensive treatment that you must be healthy enough to undergo, and you must also have a compatible donor.
What is the survival rate for AML?
This is tough to answer because there are many different types of AML, and each type has differences in treatment options and survival rates. In general:
- People younger than 65 usually fare better than older people.
- People with certain genetic mutations tend to do better than others.
- People with lower white blood cell counts at diagnosis have better outcomes.
- People without leukemia cells detected in their brains and spinal cords tend to do better.
About 50%-80% of adults with AML achieve complete remission after treatment. Remission can last months or years. Unfortunately, about 50% of those who achieve complete remission will have a recurrence. At that point, your doctor may recommend testing for a stem cell transplant, enrolling in a clinical trial, or additional chemotherapy.
Your doctor will do a staging workup after your diagnosis, which will give them a better idea of your prognosis based on your specific medical situation.
