Acute Myeloid Leukemia (AML)

What is acute myeloid leukemia?

In acute myeloid leukemia (AML), white blood cells, produced in bone marrow, are abnormal and do not become healthy cells. These abnormal cells crowd out the normal ones, so the patient’s body has a harder time fighting off infection.

How common is acute myeloid leukemia?

• Only about 500 children are found to have AML in the U.S. each year. (It is much more common in adults.) However, it is the most common second cancer among children treated for other cancers.
• The number of children with AML is about equal between boys and girls and between whites and African-Americans.
• AML is also seen more often in people who are exposed to large amounts of radiation and some kinds of chemicals.

What are the symptoms of acute myeloid leukemia?

If your child has AML, the following symptoms may be present:

• Fever
• Infection
• Easy bruising and bleeding
• Frequent nosebleeds
• Bleeding that is hard to stop, even from a small cut
• Pain in bones or joints
• Swollen glands
• Poor appetite

How is acute myeloid leukemia treated?

Chemotherapy (“chemo”) is the primary AML treatment:

• Chemotherapy (“chemo”) - uses powerful medicines to kill cancer cells or stop them from growing (dividing) and making more cancer cells.
  • Chemo may be injected into the bloodstream, so that it can travel throughout the body.
  • Some chemo may be given by mouth.
  • Combination therapy uses more than one type of chemo at a time.

Doctors look at several factors to decide which medications to use and how aggressive treatment should be. Some of these factors include the child’s age and the child’s white blood cell count before treatment.

Expect your child’s AML treatment to include two phases:

• Induction - to kill the leukemia cells in the blood and bone marrow and put the disease into remission (a return to normal blood cell counts)
  • Central nervous system (CNS) sanctuary therapy (also called CNS prophylaxis) - may also be given during this time to kill leukemia cells that remain in the brain and spinal cord after standard chemo. With this treatment, chemo medications are injected into the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord.
• Consolidation/intensification/post-induction - to rid the body of any remaining cells that could begin to grow and cause the leukemia to return (relapse). This begins after remission has been confirmed and may continue for two or three more years.

St. Jude investigators have pioneered methods to detect a very small number of leukemia cells that stay in the bone marrow after the completion of the induction therapy. These methods can detect a single AML cell among 1,000 normal cells. Children who have more than one cell in 1,000 after completing the induction phase are at the greatest risk of relapsing.

• Stem cell transplant - may be used for a child who is at high risk of relapse or who has AML that is resistant to other treatments. A stem cell transplant includes replacing blood-forming cells in the bone marrow that have been killed by chemo and/or radiation therapy:
  • A stem cell transplant gives the patient new blood cells from a donor’s blood or bone marrow. These cells grow into healthy blood cells to replace the ones the child lost.
  • Some types of stem cell transplants may be called “bone marrow transplants” because the cells come from the donor’s bone marrow.
• Immunotherapy - uses specific types of cells called natural killer (NK) cells. These cells are obtained from parents and are given to patients with the goal of eliminating leukemia cells.
  • NK cells are harvested from the blood of one of the parents. The cells are then infused into the child’s blood.
  • The NK cells circulate in the child’s body and recognize and attach to the leukemia cell wall.
  • NK cells damage the cell walls of the AML cells, leading to their destruction.
• Radiation therapy - uses high-energy X-rays or other types of radiation to kill cancer cells or stop them from growing. This is rarely used in AML treatment.

What are the survival rates for acute myeloid leukemia?

• About 90 percent of children with AML have no cancer cells in their blood after induction. However, AML later returns in about 20 percent of these cases.
• Five-year survival rates range from 65 to 75 percent.

Why choose St. Jude for your child’s leukemia treatment?

• St. Jude is the only National Cancer Institute-designated Comprehensive Cancer Center devoted solely to children.
• St. Jude has created more clinical trials for cancer than any other children’s hospital in the United States.
• The nurse-to-patient ratio at St. Jude is unmatched—averaging 1:3 in hematology and oncology, and 1:1 in the Intensive Care Unit.
• The hospital’s leukemia studies have pioneered the way the world treats childhood leukemia.
• St. Jude pioneered outpatient clinical trials for children with leukemia, reducing the need for inpatient stays.
• St. Jude scientists are using new forms of treatment to improve the outcome of AML. Current clinical trials include:
  • Treatment based on the specific subtype of AML and on the response to therapy: intensive use of chemo plus stem cell transplant
  • Checking for minimal residual disease by flow-cytometric and molecular techniques
  • Clofarabine, sorafenib and other new drugs for the treatment of AML
  • Natural killer cell transplantation
  • Using new methods to look for genetic defects in AML