What Is Acute Myeloid Leukemia (AML)? Symptoms, Causes, Diagnosis, Treatment, and Prevention

This cancer is fast-growing (acute) and tends to move quickly into the blood before sometimes spreading to other parts of the body.

Understanding AML requires knowing a bit about the different kinds of cells in bone marrow. One important type is a blood stem cell, an immature cell that is capable of developing into either lymphocytes (a kind of white blood cell) or myeloid cells (which develop into red blood cells, white blood cells, or platelets). AML is thought to arise from a type of stem cell called a common myeloid progenitor, which can turn into a subset of white blood cells called myeloid cells. They can also turn into red blood cells or platelets.

AML affects the myeloid cells, particularly the ones that would develop into white blood cells.

Types of AML

There are many different AML subtypes, defined according to several criteria.

Most people with AML have the myeloid leukemia subtype, while others may have a type called monoblastic or monocytic leukemia (the cells look like white blood cells called monocytes). AML cells can also be a mixture of different types.

In rare cases, AML develops from cells that produce red blood cells (a subtype called erythroid) or platelets (a subtype called megakaryocytic).

Acute promyelocytic leukemia (APL) is a unique subtype in which the cancer cell stops maturing at the promyelocyte or progranulocyte stage.

What Causes Acute Myeloid Leukemia (AML)?

How Does AML Affect the Body?

AML is a complex disease that can impact the body in myriad ways.

As AML cells proliferate in the bone marrow, they squeeze out healthy blood-producing cells. That means the body doesn’t have enough red blood cells, white blood cells, and platelets to maintain normal function.

Red blood cells carry oxygen from the lungs to tissues throughout the body. When a person has too few of these cells, they may experience fatigue, weakness, and dizziness, among other symptoms.

Because white blood cells fight infection, a person with AML may have trouble recovering from an infection or find themselves contracting one infection after another.

Platelets help a person stop bleeding. Low blood platelet counts can lead to a host of problems, including unusual bruising and excessive bleeding.

With AML, cancer cells generally move quickly from the bone marrow into the blood. As the cells spread throughout the body, they can cause bone or joint pain, abdominal swelling, lumps or spots on the skin, and other changes.

AML can sometimes spread to other organs. When it affects the brain and spinal cord, it can cause symptoms like headaches and weakness.

Nonspecific Symptoms

People with AML may have general (nonspecific) symptoms that overlap with those of other, much more common health conditions. These include:

• Weight loss
• Fatigue
• Fever
• Night sweats
• Appetite loss

Symptoms Typical of AML

Because AML cells crowd out healthy blood-making cells in the bone marrow, people with AML may not have enough red blood cells, white blood cells, or platelets. This can cause the following symptoms typical of a blood disorder:

• Fatigue
• Weakness
• Feeling cold
• Feeling dizzy or light-headed
• Headaches
• Pale skin
• Shortness of breath
• Infections, often with a fever
• Bruises on the skin
• Excess bleeding, nosebleeds, bleeding gums, or heavy menstrual bleeding

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Risk Factors for Acute Myeloid Leukemia (AML)

Researchers have identified a number of risk factors that raise the odds that a person will develop AML. These include:

• Age The median age of AML onset is around 68, although younger people can and do develop the disease.
• Gender Men are at slightly higher risk than women.
• Smoking
• Long-term chemical exposure, for instance to benzene
• Chemotherapy treatment
• Radiation exposure or radiation treatment for cancer
• Blood disorders, such as myelodysplastic syndrome (MDS), and myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocytopenia (ET), and myelofibrosis (MF).
• Genetic syndromes, such as Down syndrome
• A close relative (a parent or sibling) with AML is a risk factor for the disease, though AML doesn’t appear to have a strong link to heredity. The genetic and chromosomal changes that trigger the disease typically occur during one’s lifetime — researchers describe them as acquired rather than inherited.

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Researchers don’t know why some at-risk people develop AML and others don’t, or why some people with no risk factors get sick. They speculate that most cases may be due to random events that occur within cells, without a specific external cause.

Doctors perform a number of laboratory tests to diagnose AML, some of which may be repeated during and after treatment to assess how well the patient is doing.

Complete Blood Count (CBC) This is a blood test that measures levels of red blood cells, white blood cells, and platelets in the blood. Low numbers — or very high numbers of white blood cells — can be a sign of AML.

Peripheral Blood Smear This is a blood test that looks for immature white blood cells called leukemic blast cells (myeloblasts). Blast cells in the blood can indicate AML.

If blood tests sound an alarm, doctors will typically perform two bone marrow tests to confirm an AML diagnosis: a bone marrow aspiration and a bone marrow biopsy.

Bone Marrow Aspiration Done under local anesthetic, this test involves inserting a special needle into the bone (usually the back of the pelvic bone) to remove a sample of liquid marrow.

Bone Marrow Biopsy Doctors generally perform a bone marrow biopsy at the same time as a bone marrow aspiration, removing a small amount of bone filled with marrow.

Pathologists study these marrow samples under a microscope to look for either an abnormally high percentage of blast cells (at least 20 percent) or blast cells with certain chromosomal changes.

Prognosis of Acute Myeloid Leukemia (AML)

AML survival rates are higher in younger adults than older ones. In younger adults, treatment is successful in the long term for 50 to 60 percent of patients younger than 60 with AML classified as favorable, according to the American Society of Clinical Oncology. Fewer than 10 percent of patients younger than 60 will survive a cancer classified as unfavorable, however.

In general, older people with AML — who make up the vast majority of people diagnosed with the disease — face a grim prognosis. Overall, fewer than 5 percent are alive five years after diagnosis, compared with 40 percent of younger patients.

There are a number of potential reasons for this. Older patients may be in poor health in general and unable to tolerate aggressive therapy. There’s also evidence that elderly patients are more likely than younger ones to have AML cells with multiple chromosomal abnormalities — a form that is extremely difficult to treat.

The duration of AML varies from patient to patient. Some will have to be on treatment for the rest of their lives, while others may be able to achieve a lasting remission.

Treatment for AML depends on a number of factors, including the subtype, the morphology (what the cancer cells look like under a microscope), and the cytogenetics (the chromosome changes in the cancer cells).

Chemotherapy

Chemotherapy (aka chemo) — the use of drugs to kill the rapidly dividing cancer cells — is typically the go-to treatment.

Chemotherapy involves three phases:

• Induction Therapy This is the first period of chemo treatment after diagnosis. Most patients stay in the hospital for three to five weeks, receiving a drug regimen that includes cytarabine (Cytosar-U) and an anthracycline medication, such as Cerubidine (daunorubicin) or idarubicin (Idamycin).
• Post-Remission Therapy The patient receives additional chemo drugs to destroy any lingering, undetectable cancer cells.
• Consolidation Therapy Patients in remission who are healthy enough to tolerate this treatment typically receive two to four rounds of high- or intermediate-dose cytarabine or other intensive chemo every month. Patients who are more fragile may undergo a different regimen. If the subtype of AML makes it resistant to chemo, doctors may recommend a stem cell transplant.

Stem Cell Transplantation

Also called a bone marrow transplant, this approach involves chemotherapy, too. Doctors use high-dose chemotherapy to destroy cancer cells in the bone marrow, blood, and elsewhere in the body. Then they replace these cells with blood-forming cells called hematopoietic stem cells. The stem cells develop into healthy bone marrow.

Targeted Therapy

This is an emerging field that focuses on unique traits of cancer cells, such as specific genetic mutations or proteins. Drugs that attack these targets can block the growth and spread of cancer cells while limiting damage to healthy tissue.

Complementary and Alternative Therapies

Though they aren’t intended to treat or cure AML, some alternative or complementary approaches may help patients cope with side effects from treatment or the disease itself. But it’s important to check with your doctor if you are considering these options, since they may affect your other therapies.

• Massage
• Acupuncture
• Exercise
• Meditation
• Yoga or tai chi
• Journaling
• Music therapy

Refractory vs. Acute AML

Your doctor may make decisions about how to manage and further treat your cancer depending on whether the disease is refractory or acute.

Refractory AML

When cancer cells are still detectable after initial treatment, the patient is said to have refractory AML.

Some patients require more than one course of treatment to achieve remission.

The U.S. Food and Drug Administration (FDA) has approved a number of drugs for refractory AML:

• enasidenib (Idhifa)
• gemtuzumab ozogamicin (Mylotarg)
• ivosidenib (Tibsovo)
• gilteritinib (Xospata)

If AML doesn’t respond to treatment, doctors may shift their efforts to controlling symptoms, known as palliative care.

As the cancer cells grow in the bone marrow, they may cause pain. Radiation therapy and pain-reducing medication can make the patient more comfortable.

Fatigue due to low red blood cell counts can be another symptom. Blood transfusions and medication can bring energy levels back up.

Doctors may prescribe anti-nausea drugs as well as high-calorie food supplements to cope with loss of appetite.

Relapsed AML

If AML returns after a period of remission it is called relapsed or recurrent AML.

Treatment for relapsed AML may involve the drugs used to treat the AML initially, perhaps in new combinations or at a different pace.

FDA-approved drugs for relapsed AML are the same as those for refractory AML.

Treatment for relapsed AML may involve a stem cell transplant or a therapy being investigated in a clinical trial.

Patients with relapsed AML may experience the same symptoms they did with their initial AML, including fatigue and repeated infections.

They may also experience less common symptoms, such as swollen lymph nodes. These may appear as lumps or bumps on the neck, armpit, and groin.

Prevention of Acute Myeloid Leukemia (AML)

• Not smoking
• Avoiding cancer-causing agents, such as benzene
  

Complications can arise from AML itself or the therapies used to treat it.

• Bleeding Low levels of platelets in the blood may cause easy bleeding and bruising. Serious bleeding, which is considered a medical emergency, can occur inside the skull, lungs, or stomach.
• A Weakened Immune System Many medicines used to treat AML can weaken the immune system and increase the risk of infections. Symptoms to watch out for include fever, sore throat, body aches, and fatigue.
• Infertility Some of the treatments used for AML can cause infertility.
• Anemia With anemia, there aren’t enough red blood cells. Patients might feel tired, weak, or out of breath.
• Tumor Lysis Syndrome It happens when many cancer cells die in a short period of time and release their contents into the blood. This can cause severe damage to the kidneys and heart if untreated.
• Differentiation Syndrome Certain medicines, such as all-trans retinoic acid (ATRA), enasidenib, and vosidenib, can cause this potentially life-threatening complication. It’s characterized by fever, trouble breathing, swelling in the limbs, a drop in blood pressure, and fluid buildup around the lung or heart. Treatments should be given as soon as patients develop symptoms.

AML is one of the most common types of leukemia, but it is still rare, making up only about 1 percent of all cancers.

Men are slightly more likely to get this cancer than women, but the average lifetime risk for both sexes is low — about 0.5 percent.

Researchers say many factors, including socioeconomic status and access to medical care, likely account for these disparities.

Some conditions closely related to AML include:

• Anemia
• Leukemia
• Chronic lymphocytic leukemia
• Harry cell leukemia

If you’ve been diagnosed with AML, there are many resources available to help you through your journey. Here are some of Everyday Health’s favorites.

Leukemia & Lymphoma Society (LLS)

The LLS is dedicated to funding blood cancer research and providing education and patient services. In addition to delivering a wealth of information about AML, we like their peer-to-peer program that connects you with trained volunteers. You can also locate a support group in your area.

National Cancer Institute (NCI)

This federally funded organization offers helpful statistics and information about different types of cancer. You can search for clinical trials on their site.

American Cancer Society (ACS)

The ACS provides educational information for all types of cancer, including AML. You might want to take advantage of their 24/7 cancer helpline.

Cancer.Net

This site, sponsored by the American Society of Clinical Oncologists (ASCO), provides useful information about living with AML. From treatment options to coping with the emotional side effects of cancer, they’ve got you covered.

CancerCare

This organization offers free support services for people affected by leukemia. They also provide lots of helpful resources for financial assistance.

Be the Match

Be the Match, which is operated by the National Marrow Donor Program, manages the most diverse marrow registry in the world to help transplant patients find a life-saving donor match. They also offer various support programs and ways for patients to connect with others.

LLS Health Manager App

The LLS Health Manager is a free app designed to help patients with leukemia, lymphoma, and myeloma take control of their health. You can search for recipes, plan meals, and create grocery lists. You can also track your treatment side effects and medications.

Additional reporting by Julie Marks.