Leukemias are cancers of the blood and bone marrow in which the body makes abnormal blood cells that crowd out the normal ones. Leukemias and brain tumors account for more than half of pediatric cancers.

Two of the most common childhood leukemias are:

• Acute lymphoblastic leukemia. This is the most common cancer that develops in children. It arises when the bone marrow makes white blood cells (lymphocytes) that don't fully develop and are not healthy. The body does not make enough white blood cells or platelets, making the patient vulnerable to infection and bleeding. Acute lymphoblastic leukemia must be treated quickly to prevent it from worsening.
• Acute myeloid leukemia. This cancer also develops when the bone marrow makes white blood cells that don’t fully develop and are not healthy. Here again, the body does not make enough white blood cells or platelets, making the patient vulnerable to infection and bleeding. As an acute leukemia, this leukemia must also be treated quickly or it will get worse. Other similar leukemias that can occur in childhood include:
  • Chronic myelogenous leukemia
  • Juvenile myelomonocytic leukemia (JMML)
  • Transient myeloproliferative disorder (in Down syndrome patients)
  • Myelodysplastic syndromes

Symptoms of Pediatric Leukemia

Symptoms vary depending on the type of cancer. Many of the symptoms of childhood cancers can also be symptoms of other diseases. Be sure to consult your doctor if your child has symptoms that seem unusual for him or her.

Symptoms of leukemia may include:

• Fever
• Fatigue
• Bruising or bleeding easily
• Bone pain

Stages

Because leukemias are cancers of the blood, which spreads throughout the body, they are not divided into stages that indicate how far they have spread. Instead, they are divided into risk groups or treatment categories.

Acute lymphoblastic leukemia (ALL)

ALL is classified into risk groups.

• Standard risk: The patient is between one and nine years old and has a white blood cell count of less than 50,000 µl.
• High risk: The patient is less than one year old or older than 10, or has a white blood cell count greater than 50,000 µl. Patients in the high risk group are treated more aggressively than patients who are considered standard risk.

ALL can also be classified according to the status of treatment:

• Diagnosed: The leukemia hasn’t been treated except to relieve fever or other symptoms. In addition, more than 20 percent of the bone marrow cells are leukemia cells, or, less than 20 percent of the bone marrow cells are leukemia cells and there is a specific change in the chromosomes.
• In remission: The leukemia has been treated, and less than 5 percent of the bone marrow cells are leukemia cells. There are no signs of the disease in the brain, spinal cord, or other parts of the body, and the complete blood count is almost normal.
• Recurrent or relapsed: The leukemia has been treated and has come back, either in the blood, bone marrow, or other parts of the body.

Acute myeloid leukemia

Like ALL, acute myeloid leukemia and other myeloid cancers are also classified according to the status of treatment. There are some specific genetic changes (chromosome translocations) that are associated with better or worse prognosis.

• Diagnosed: The leukemia hasn’t been treated except to relieve fever or other symptoms. In addition, more than 20 percent of the bone marrow cells are leukemia cells, or, less than 20 percent of the bone marrow cells are leukemia cells and there is a specific change in the chromosomes.
• In remission: The leukemia has been treated, and less than 5 percent of the bone marrow cells are leukemia cells. There are no signs of the disease in the brain, spinal cord, or other parts of the body, and the complete blood count is almost normal.
• Recurrent or relapsed: The leukemia has been treated and has come back, either in the blood, bone marrow, or other parts of the body.

Treatment for Leukemias

Chemotherapy and radiation therapy (in selected cases) are the standard treatments for many childhood cancers. Your child may receive one or more treatments depending on the cancer type, your child’s general health, and other factors.

Chemotherapy

Leukemias in children are primarily treated with chemotherapy (although radiation may also be used). In some cases chemotherapy may be combined with a stem cell transplant.

For acute lymphoblastic leukemia, systemic chemotherapy is often combined with chemotherapy administered to the spinal fluid, either to treat cancer that has spread around the spinal cord or brain or to prevent it from spreading there.

Targeted therapy

Targeted therapy consists of drugs that can stop tumors from growing by pinpointing the changes in genes that lead to cancer. Targeted therapy may be used to treat brain tumors, leukemias, and sarcomas.

Other drug therapy

Other types of drugs are used to treat certain types of myeloid leukemias by killing leukemia cells, preventing them from multiplying, or helping them mature into normal white blood cells. These drugs include arsenic trioxide and all-trans retinoic acid.

Watchful waiting

For some leukemias or myeloid cancers, the doctor may monitor a patient closely without giving treatment until symptoms change. This watchful waiting is used with myelodysplastic syndromes and transient myeloproliferative disorder.

Learn more about pediatric cancer:

• Chemotherapy for Pediatric Cancer
• Radiation Therapy for Pediatric Cancer
• Pediatric Cancer Risk Factors
• Late Effects of Pediatric Cancer Treatment