Mixed Phenotype Acute Leukemia

What is mixed phenotype acute leukemia?

Mixed phenotype acute leukemia is two forms of leukemia combined: acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). The term “mixed phenotype” means “both types.”

Leukemia is a type of cancer that attacks blood-forming cells in the bone marrow. Leukemias that spread quickly are called acute leukemias. The fast-moving nature of mixed phenotype acute leukemia means it is especially crucial for people who are newly diagnosed to be treated quickly.

How common is mixed phenotype acute leukemia?

Mixed phenotype acute leukemia is rare, representing just 2-3% of all acute leukemia cases. It is more common in adults than children, but it can occur at any age.

What are the signs and symptoms of mixed phenotype acute leukemia?

Symptoms of mixed phenotype acute leukemia are similar to other acute types of leukemia:

• Fever
• Bruising or bleeding
• Pale skin
• Appetite loss or decrease
• Fatigue
• Weight loss

Doctors working to diagnose a person might also discover symptoms such as anemia, enlarged liver or spleen, or a reduced numbers of blood cells.

How is mixed phenotype acute leukemia treated?

The treatment for mixed phenotype acute leukemia is decided based on how the leukemia cells look under a microscope. There are two phases of treatment:

Induction—This phase focuses on ridding the body of leukemia. The person then stays in or near the hospital for several weeks afterward to recover from the treatment and to avoid infections that may occur because of a weak immune system.

Post-remission—AfterOnce the chemotherapy kills most of the leukemia cells, treatment focuses on destroying any remaining hidden cancer cells, which are often present in acute leukemias. Treatment may include more chemotherapy or stem cell transplant.

Four types of treatment may be used during any of these treatment phases:

• 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 blood stream, 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.
• 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 patient lost.
  • Some types of stem cell transplants may be called “bone marrow transplants” because the cells come from the donor’s bone marrow.
• Radiation therapy—uses high-energy X-rays or other types of radiation to kill cancer cells or stop them from growing.
• Targeted therapy—uses medicines or other treatments that target and attack specific cancer cells without harming normal cells.

What are the survival rates for mixed phenotype acute leukemia?

Mixed phenotype acute leukemia can be hard to treat because of how quickly it grows, and because it has features of both acute myeloid leukemia and acute lymphoblastic leukemia.

In children with mixed phenotype acute leukemia, the survival rate is lower than acute lymphoblastic leukemia but similar to acute myeloid leukemia. The survival rate is 50% to 75% past five years.

Fortunately, researchers are forming a better understanding of the factors that affect mixed phenotype acute leukemia prognosis. These factors include the following:

• Age (children have higher survival rates than adults)
• Previous history of mixed phenotype acute leukemia
• History of other blood disorders
• History of chemotherapy for other cancers

Why choose St. Jude for your child’s mixed phenotype acute 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.