Definition

Acute lymphoblastic leukemia (ALL) is a cancer of the blood and bone marrow. Lymphocytes are a type of white blood cell. With ALL, the bone marrow makes too many of these cells.

Leukemia cells do not function normally. In this case, they cannot fight infections. This means that the person is more likely to become infected with viruses or bacteria. The cancerous cells also overgrow the bone marrow. This forces other normal components, like platelets out. Platelets are needed to help the blood clot. As a result, people with leukemia may bleed more easily.

White Blood Cells

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Causes

The cause of ALL is unknown. Research shows that certain risk factors are associated with the disease.

Risk Factors

Risk factors that increase your chance of developing ALL:

• Sex: male
• Race: white
• Age: children and elderly (adults older than 70)
• Previous chemotherapy or radiation therapy treatment
• Exposure to atomic bomb radiation or nuclear reactor accident
• Exposure to toxic chemicals such as benzene (common in agriculture, dye works, and paint manufacturing and use)
• Certain genetic disorders, such as Down syndrome, Bloom syndrome, Fanconi's anemia, ataxia-telangiectasia, neurofibromatosis, Shwachman syndrome, IgA deficiency, and congenital X-linked agammaglobulinemia

The following risk factors are specific to childhood ALL:

• Having a brother or sister with leukemia
• Race: white or Hispanic
• Living in the United States
• Exposure to x-rays before birth
• Exposure to radiation
• Previous chemotherapy or other treatment that weakens the immune system
• Certain genetic disorders (see above)

Symptoms

These symptoms may be caused by other, less serious health conditions. You should see a doctor if you or your child is experiencing:

• Weakness
• Tiredness
• Fever
• Pale skin
• Easy bruising or bleeding
• Petechiae (flat, pinpoint spots under the skin caused by bleeding)
• Shortness of breath
• Weight loss
• Loss of appetite
• Bone or joint pain
• Stomach pain
• Pain or a feeling of fullness below the ribs
• Painless lumps in the neck, underarms, stomach, or groin
• Swelling of the liver and/or spleen

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor may also check for swelling of the liver, spleen, or lymph nodes. You will likely be referred to an oncologist. This is a doctor who specializes in treating cancer.

Tests may include the following:

• Blood tests
• Bone marrow aspiration
• Bone marrow biopsy
• Spinal tap
• Routine microscopic exam—examination of a sample of blood, bone marrow, lymph node tissue, or cerebrospinal fluid
• Cytogenetic analysis—a test to look for certain changes of the chromosomes (genetic material) of the lymphocytes; certain genetic abnormalities include:
  • Relocation of genetic material from one chromosome to another
  • Presence of a particular gene
  • Presence of a variant gene, which controls an enzyme that influences folate metabolism
• Immunophenotyping—examination of the proteins on cell surfaces and the antibodies produced by the body; to distinguish lymphoblastic from myeloid leukemia and determine types of therapy
• Tests to help the doctor see the structures in your body:
  • Chest x-ray
  • Computed tomography (CT) scan
  • Magnetic resonance imaging (MRI) scan
  • Gallium scan and Bone scan—injection of a radioactive chemical into the bloodstream to detect areas of cancer or infection
  • Ultrasound—a test that uses sound waves to examine masses and organs inside the body

Treatment

Talk with your doctor about the best plan for you. Treatment of ALL is done in two phases. First, remission induction therapy is used to kill leukemia cells. Then, maintenance therapy is used to kill any remaining leukemia cells. Cells left behind could grow and cause a relapse. Treatment options include:

Prevention

There are no guidelines for preventing ALL since its cause is unknown.