What to Know About Acute Myeloid Leukemia in Children

AML is a type of cancer that affects blood cells found in the bone marrow. More specifically, it causes the bone marrow to create a large amount of abnormal blood cells.

In a healthy person, the bone marrow makes blood stem cells known as myeloid cells. The myeloid cells then mature to either become red blood cells, white blood cells, or platelets.

But in a patient with AML, the myeloid stem cells become immature white blood cells known as myeloblasts. These myeloblasts are abnormal and never mature to become healthy white blood cells.

Over time, the buildup of myeloblasts or leukemia cells means that there’s less space for healthy red and white blood cells or platelets. As a result, a person may experience infection, anemia, or even bleed easily.

Eventually, the leukemia cells can spread to other parts of the body outside of the blood or even form solid tumors known as granulocytic sarcomas or chloromas.

AML is classified as an acute cancer. This means that without treatment, the condition can progress quickly.

It’s important to know that some of the symptoms of AML can also be present in more common conditions. So, before worrying that your child might have cancer, it’s a good idea to speak with your child’s pediatrician to rule these out first.

Common symptoms associated with AML can include:

• fever
• easily bruising or bleeding
• bleeding that’s difficult to stop, such as nosebleeds
• belly pain
• night sweats
• frequent infections
• pain in the bones or joints
• poor appetite
• shortness of breath
• feeling weak or fatigued
• swollen lymph nodes, which appear as painless lumps on the neck, stomach, underarm, groin, or other areas of the body
• skin rash that can resemble eczema patches, lumps under the skin, or discoloration like bruises

If AML is suspected, your child will undergo some tests to provide a full picture of their health. Typically, this will begin with a physical exam and collecting your child’s health history.

The next steps may include some or all of the following tests:

• Complete blood count (CBC). A CBC test shows the total number of red and white blood cells and platelets in the blood. Often, children with AML will have red blood cell and platelet numbers that are much lower than usual.
• Peripheral blood smear. This blood test looks for myeloblast cells. Children with AML will have a high number of immature myeloblasts and a low amount of mature white blood cells.
• Bone marrow testing. Your child’s doctor may order bone marrow testing to look for changes that might indicate that the bone marrow isn’t functioning as expected. Usually, a sample will be taken from the hip bone or breastbone. However, for children with easy bleeding symptoms, this test might not be done until the bleeding symptoms are under control.
• Genetic testing. Along with bone marrow testing, genetic testing can help identify genetic or chromosomal mutations. This test can help to determine the best course of treatment. Common genetic tests associated with leukemia diagnoses include:
  • cytogenetic analysis (karyotyping)
  • fluorescence in situ hybridization (FISH)
  • molecular testing

After completing the tests, physicians will review the results and determine if AML is the right diagnosis. AML is diagnosed based on the presence and amount of myeloblasts found in the blood and bone marrow samples.

A healthy person will usually only have 1 to 5 percent myeloblasts present in their blood or bone marrow. But for AML diagnosis, samples must contain at least 20 percent or more myeloblasts. However, cell counts aren’t the only criteria used for a diagnosis.

Physicians will also review chromosomal changes and characteristic markers — known as antigens — on the myeloblasts’ surface. Keep in mind that not all patients will have chromosomal or genetic abnormalities.

There are a variety of treatment options available for childhood AML. Depending on the type of AML your child has, and more specifically the cytogenetic and molecular factors present in your child’s blood, the oncologist may recommend one or a combination of the following treatment methods.

Chemotherapy

Chemotherapy is a common option for childhood AML. A two-phase approach is often used, which includes induction therapy and consolidation therapy.

Some children may undergo intensive chemotherapy for more aggressive forms of AML. Intensive chemotherapy requires ongoing cardiac function monitoring to check for any impact on the heart.

Children with Down syndrome are usually treated with less intensive chemotherapy because this subtype of AML tends to be more responsive to this treatment.

Drug therapy

Some newly diagnosed AML patients may be prescribed certain medications. There are also specialized medications given to children who have relapsed (a return of leukemia cells) or refractory (not reaching remission levels after treatment is complete) AML.

For relapsed and refractory AML patients, the duration and types of medications prescribed will vary based on the patient’s age and diagnostic results.

Stem cell transplantation

Stem cell transplantation is another treatment option for children with more aggressive forms of AML, those whose previous treatments did not work well, or those whose AML has relapsed.

Central nervous system prophylaxis

Central nervous system prophylaxis is a preventative medication that’s given to help prevent leukemia cells from spreading to the central nervous system. The medication is injected directly into the spinal fluid. This treatment is considered a standard protocol for childhood AML.

Clinical trials

While the above treatments are the standard options and tend to be fairly effective in treating childhood AML, not all cases will respond well.

In these scenarios, enrolling your child in a clinical trial might be the best course of action, as your child would have access to cutting-edge technologies and therapies. More importantly, clinical trials have strenuous oversight and are heavily regulated.

AML accounts for roughly 20 percent of all childhood leukemia cases. Depending on the type of AML your child has, the overall outlook can vary.

Children with the acute promyelocytic leukemia (APL) subtype of AML have a higher cure rate. However, this subtype only accounts for about 4 to 8 percent of all pediatric AML cases.

Along with the type of AML, the timing of when the disease is detected and how quickly treatment is started also affects outcomes.

Around 85 to 90 percent of childhood AML cases result in remission after induction therapy begins. Fewer than 15 percent of children will have refractory AML. About 30 percent will experience an AML relapse.

Overall, the 5-year survival rate for childhood AML is encouraging and ranges from 65 to 70 percent.

Cancer can be scary, especially when your child is the patient. But taking a proactive approach is the best way to give your child the best chance of beating their diagnosis.

Staying informed, building a relationship with your child’s pediatric cancer care team, and establishing a supportive network to help your family through this process are all critical to help you and your family through this situation.