Aerial view of the CHLA Anderson Pavilion Building.

Childhood Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (also known as acute lymphocytic leukemia, or ALL) is a cancer of the bone marrow and blood, primarily targeting white blood cells. It is the most common type of cancer in children.

Each year, approximately 3,000 people under 20 years old are diagnosed with ALL. The condition accounts for 30% of all pediatric cancers and is most often diagnosed in children ages 3 to 5, but it can occur at any age.

Types of Acute Lymphoblastic Leukemia

ALL differs from other cancers as it is not classified by stages. Instead, doctors classify acute lymphoblastic leukemia based on:

  • Age of Child: Under 1 year, 1–10 years, or over 10 years
  • Genetic Changes: Specific changes in genes of the leukemia cell that influence prognosis and treatment
  • Type of Lymphocytes Involved: B cells or T cells
  • Laboratory Results: White blood cell count in a blood sample and leukemia cells in the spinal fluid

Causes and Risk Factors of Acute Lymphoblastic Leukemia

Bone marrow (tissue inside the bones) normally makes two types of immature white blood cells: myeloid and lymphoid stem cells. Lymphoid stem cells develop into lymphoblasts, which become one of three types of mature white blood cells (lymphocytes). The three lymphocytes and their functions include:

  • B Lymphocytes: Create antibodies and help the body fight infection and disease
  • T Lymphocytes: Help B cells create antibodies and can kill tumor cells and infected cells
  • Natural Killer Cells: Attack cancer and other viruses

Children with ALL have too many abnormal lymphoblasts. These abnormal cells (leukemia cells) outnumber healthy cells in the bone and bone marrow, weakening the immune system and making it difficult to fight infection and disease.

The exact cause of the genetic changes that cause ALL is unknown but known risk factors include:

  • Gender: Males are more likely than females to be diagnosed with ALL
  • Ethnicity: Hispanic children show a higher incidence compared to white and Black children
  • Exposure: Radiation exposure or chemotherapy treatment increases risk
  • Genetic Disorders: Conditions such as down syndrome, Li-Fraumeni syndrome, ataxia-telangiectasia and neurofibromatosis are associated with higher risk
  • Family History: The risk of a sibling developing ALL is slightly higher than other children, but is overall low

Signs and Symptoms of Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia can affect many areas of the body. Children may experience fever, frequent infections, and easy bruising or bleeding.

Other common symptoms are:

  • Abdominal pain or feeling of fullness below the ribs
  • Bone or joint pain
  • Dark-red, flat spots under the skin (petechiae)
  • Difficulty breathing
  • Fatigue
  • Painless lumps in the stomach, neck, underarm or groin
  • Pale appearance
  • Weakness

Diagnoses for Acute Lymphoblastic Leukemia

To diagnose acute lymphoblastic leukemia, doctors evaluate medical history, current symptoms, and conduct a physical exam.

Standard diagnostic tests typically include:

  • Complete Blood Count (CBC): Measures the number of white blood cells, red blood cells and platelets
  • Bone Marrow Test or Biopsy: Bone marrow sample is examined for leukemia cells
  • Lumbar Puncture (Spinal Tap): Spinal fluid sample is used for analysis of leukemia cells
  • Imaging Studies: X-ray, ultrasound, and/or computed tomography (CT) scans may be needed based on symptoms
  • Specialized Tests: Genetic testing of leukemia cells provides additional information to establish a prognosis and guide treatment options

Treatment for Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia can progress quickly, but early treatment cures most children.

Treatment options for ALL depend on factors, such as your child’s age, symptoms and risk group. Children with higher white blood cell counts, for instance, will receive more intensive treatment. Antibiotics may also be used to prevent or treat infections.

Treatment options for acute lymphoblastic leukemia include:

  • Chemotherapy: Multiple chemotherapy drugs in combination over the span of two to three years.
  • Antibody-based immunotherapy: New therapies that target antigens on the surface of the leukemia cell. Some examples are blinatumomab and inotuzumab ozogamicin.
  • Targeted Therapy: Uses drugs to target and treat specific leukemia cells, based on the genetic changes in the leukemia cell.
  • Radiation Therapy: Uses high-energy beams to destroy cancer cells.
  • Chemotherapy with Stem Cell Transplant (Bone Marrow Transplant): Uses high doses of chemotherapy to destroy unhealthy blood-forming cells in the bone marrow, followed by a transplant of healthy stem cells from a donor to replace them.
  • Chimeric antigen receptor (CAR)-T cell therapy: An immunotherapy that uses a patient’s own T-cells, white blood cells that are part of the immune system, to recognize and attack cancer cells. The T-cells are modified in the lab and then infused back into the patient.
  • Gene therapy: Targets the underlying cause of the disease and treatment options are available for ALL at CHLA.
  • Clinical Trials: As a research hospital, CHLA is a research hospital with participation in over 250 clinical trials, offering innovative treatments and therapies that may not be accessible elsewhere. We offer access to eligible patients to access promising new medications and treatments that are not widely available.

Treatment for newly diagnosed ALL can last up to three years, starting with the most intensive therapies. The process is divided into three phases, including:

  • Induction: Targets and kills most of the leukemia cells in the blood and bone marrow
  • Consolidation: Eliminates any remaining leukemia cells
  • Maintenance: Prevents new leukemia cells from growing

Standard doses of chemotherapy may not effectively reach leukemia cells in the brain and spinal cord, or central nervous system (CNS). To prevent the spread of leukemia cells to the CNS, doctors may recommend additional treatment known as CNS directed therapy which includes spinal taps with the administration of chemotherapy directly into the spinal fluid.

Most children have regular follow-up exams and imaging to screen for recurrence (cancer that comes back) and manage any complications.

Cell and Gene Therapy Treatment for Acute Lymphoblastic Leukemia

Children’s Hospital Los Angeles is one of the nation’s leading authorities, and premier leader in California, in pediatric gene therapy–a newer, cutting-edge approach to treating acute lymphoblastic leukemia that targets the root cause, modifies specific genes to transform them, and improve the body’s ability to fight the disease. CHLA offers Kymriah®, which is an FDA-approved gene therapy treatment option for children and young adults with relapsed or treatment-resistant B-cell ALL. During this treatment, doctors collect bone marrow cells from the patient, modify them in a lab, and reintroduce them to target and destroy cancer cells. Omisirge®, a cell therapy offered at CHLA, is approved for patients with leukemia who need a bone marrow transplant and helps minimize infection. Both of these treatments offer hope to patients where other treatments may not have worked.

CHLA played a pivotal role in the clinical trials that led to the FDA approval of Kymriah and is one of the few centers in Southern California to offer both Kymriah and Omisirge. Learn more about cell and gene therapy at CHLA.

In addition, several clinical trials of newer CAR T-cell therapies for B-ALL and T-ALL are also offered at CHLA.

Acute Lymphoblastic Leukemia Care at Children’s Hospital Los Angeles

Our Leukemia and Lymphoma Program is one of the largest programs on the West Coast, with specialists internationally recognized for their expertise in treating acute lymphoblastic leukemia, including innovative therapies for resistant cases and gene therapy. With decades of advancing leukemia care through research, CHLA participates in international clinical trial networks and offers early-phase trials available at select centers nationwide. Discover the comprehensive ALL treatment options available through our Leukemia and Lymphoma Program at CHLA.

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