Acute lymphoblastic leukemia affects white blood cells called lymphocytes.
Acute lymphoblastic leukemia (ALL) is a cancer of the blood and bone marrow. It is the most common form of childhood cancer.
In leukemia, cancer cells grow rapidly in the bone marrow. When this happens, healthy blood cells — white blood cells, red blood cells, and platelets — cannot do their jobs correctly.
ALL affects white blood cells called lymphocytes. These cells fight infection and help protect the body against disease.
There are 2 types of lymphocytes: B lymphocytes and T lymphocytes. ALL may arise from either type of lymphocyte. Cases of ALL are known as either B cell or T cell ALL. B cell ALL is more common.
About 3,000 children and teens are found to have ALL each year in the United States.
ALL occurs most often in children ages 2–5. It is also found in older children and teens.
ALL in infants is rare. The U.S. sees about 90 cases of ALL in children younger than 1 each year.
Chemotherapy is the most common treatment for ALL. The overall cure rate is about 90% in the U.S.
Symptoms of acute lymphoblastic leukemia
Acute leukemia means symptoms get worse quickly. Children may need medical attention right away.
The most common signs and symptoms of ALL are:
Pain or fullness below the ribs (enlarged liver and/or spleen)
Children with leukemia usually have a high number of white blood cells in their blood.
Doctors may suspect leukemia after:
Doing a physical exam
Taking a health history
Looking at the results of blood tests
Children with leukemia usually have a high number of white blood cells in their blood.
Physical exam and health history
During the exam and history, the provider will:
Check general signs of health, including signs of disease, such as lumps or other unusual symptoms.
Examine the eyes, mouth, skin, and ears. The provider will feel the belly for signs of an enlarged spleen or liver. In boys, the provider may also examine the testes.
Ask about other health conditions, including illnesses that relatives such as parents, siblings, and grandparents have had. The provider is looking for inherited conditions that may increase cancer risk.
Blood and bone marrow tests
Blood and bone marrow tests are used to diagnose ALL.
A provider will draw blood to run tests. These tests include:
Complete blood count – This test checks the counts of different types of blood cells. In ALL, the blood may have too many white blood cells. Many of these cells will be cancer cells.
Blood chemistry studies – This test checks the amounts of certain substances in the blood. An unusual level (either higher or lower than normal) can be a sign of disease.
Liver function tests
Coagulation test – This test measures the blood’s ability to clot.
Bone marrow aspiration and biopsy are 2 tests that will confirm a diagnosis of cancer. Patients usually have these procedures at the same time. They will either be sedated or receive pain medicine.
Tests after ALL diagnosis
If leukemia is found, the care team will run more tests.
These include lab tests to identify specific genes, proteins, and other factors involved in the leukemia.
This is important because cancer is caused by mistakes (mutations) in the cell’s genes. Identifying these mistakes may help diagnose the specific subtype of leukemia.
Doctors use these details to choose treatment options tailored to your child’s case.
The care team also will run tests to find out if cancer is in other parts of the body:
Lumbar puncture
A lumbar puncture will show if leukemia has spread to the brain and spinal cord. The test is also called an LP or spinal tap.
Patients may get chemotherapy at the same time this is done. This is called prophylactic intrathecal chemotherapy. It is given to prevent ALL from spreading to the cerebrospinal fluid.
Chest x-ray
A chest x-ray will show if leukemia cells have formed a mass in the middle of the chest.
The goal of this phase is to kill leukemia cells in the blood and bone marrow and bring the disease into remission. This phase is intense and may require hospital stays.
Central nervous system (CNS) sanctuary therapy may be given to destroy leukemia cells in the spinal fluid.
Doctors will look at several factors to plan next steps:
Doctors will consider age of the patient and white blood cell counts, one of the risk factors of relapse.
By the end of induction phase, doctor will know the results of genetic testing. This is another important factor to determine the risk.
Many pediatric centers use highly sensitive tests to measure for minimal residual disease (MRD). Positive MRD indicates a greater risk of relapse and need for more intense therapy.
If the leukemia stays in remission, maintenance therapy can begin. Its goal is to destroy any leukemia cell that might remain after the first 2 phases.
Patients will likely have weekly chemotherapy and blood tests with periods of high-dose chemotherapy known as reinduction.
The first 6–9 months of this phase is usually intense. Often patients can return to school after 6–9 months.
Follow-up schedule
Year 1
The patient will return for follow-up visits once every 1–4 months.
These visits may include:
Physical exam and medical history
Blood tests and other lab tests
Year 2
Follow-up visits may change to once every 6 months.
Years 3-5
Follow-up visits may change to once a year.
Treatment of acute lymphoblastic leukemia
Central venous device
Patients will have a surgical procedure to get a central venous access device. This device reduces the need for needle sticks. It allows patients to have blood drawn for lab tests and get intravenous (IV) medicines, fluids, blood products, and nutrition.
Chemotherapy
Chemotherapy is the main treatment for childhood ALL. It involves several medicines and takes 2–3 years to complete. It is divided into 3 phases:
1. Induction
The goal of this phase is to kill leukemia cells and bring the disease into remission. This part usually lasts 4-6 weeks.
Central nervous system sanctuary therapy (also called CNS prophylaxis) is given during this time. Its aim is to kill leukemia cells in the spinal fluid. Drugs are injected into the fluid-filled space between the thin layers of tissue that cover the spinal cord. This is called intrathecal chemotherapy.
Patients will have a bone marrow aspirate or biopsy during this phase to find out how the treatment is working.
2. Consolidation/intensification
The goal of this phase is to kill cells that remain and could cause the leukemia to come back. This part can last several months.
Medicines may include cyclophosphamide, cytarabine, 6-mercaptopurine (6-MP), thioguanine, vincristine, corticosteroids, and caraspargase. Methotrexate with or without leucovorin rescue may also be given.
3. Maintenance/continuation
The goal of this phase is to kill cancer cells that might have survived the first 2 phases. Maintenance may last 2–3 years.
It may involve daily doses of 6-mercaptopurine (6-MP), weekly methotrexate, and doses of vincristine and corticosteroids.
In higher-risk patients, anthracycline drugs such as doxorubicin/daunorubicin as well as cyclophosphamide and cytarabine may be given.
After initial treatment, patients usually are cared for on an outpatient basis. But there may be times when the patient will need to be in the hospital.
Many cancer centers and hospitals in the United States treat ALL. The specific drugs, dosage, and schedule of delivery may vary. But the treatment principles are the same.
The treatment plan will depend on results of the patient’s diagnostic tests. In some cases, doctors may suggest more treatment options such as targeted therapy, immunotherapy, or a stem cell transplant (bone marrow transplant).
Targeted therapy for acute lymphoblastic leukemia
Targeted therapies work by acting on, or targeting, specific features of tumor cells. In some tumors, there are changes in the genes and proteins that control tumor cell growth and division.
Scientists are testing drugs to see if they can block the signals that cause certain types of cancer cells to grow.
Targeted therapy drugs, such as imatinib, dasatinib, and ponatinib have been shown to be effective in treating types of ALL called Philadelphia chromosome-positive ALL and Philadelphia-like ALL.
A drug called venetoclax may be used to treat ALL.
Immunotherapy for acute lymphoblastic leukemia
Immunotherapy is a type of cancer treatment that uses the immune system to fight cancer. It works by helping the immune system find and kill cancer cells.
Stem cell (bone marrow) transplant for acute lymphoblastic leukemia
A stem cell transplant may be recommended for children who are at high risk for relapse or whose treatment does not work. Patients must be medically able and have a suitable donor.
Doctors sometimes look at how well induction chemotherapy worked to decide whether a transplant is needed.
Radiation therapy for acute lymphoblastic leukemia
Radiation is rarely used in ALL treatment. It may be given in cases where ALL has spread to the brain, spinal cord, or testicles.
Radiation may also be given to prepare patients to receive a stem cell transplant.
Risk group
Doctors can tailor treatments to patients based on their risk group.
Risk group refers to the chance that the cancer will not respond to treatment (refractory) or will return (relapse). There are treatment options for relapsed or refractory ALL.
Risk groups include low, standard, high, and very high.
The method of chemotherapy and types of medicine depend on the child’s risk group. For example, children and teens with high-risk leukemia receive more anticancer drugs and/or higher doses than children with low risk ALL.
Risk groups are determined by:
Whether the cancer began in B-lymphocytes or T-lymphocytes: B-cell ALL is considered lower-risk than T-cell ALL.
Age: Children ages 1–9 with B-cell ALL are generally considered low-or standard-risk. Children younger than 1 and children 10 or older are considered high-risk patients. (This age cut-off may vary among treatment centers.)
White blood cell count at diagnosis: Children with a count below 50,000 are considered low-risk.
Certain changes in the chromosomes or genes
Whether leukemia cells are found in the cerebrospinal fluid (CSF) at the time of diagnosis: If cells have spread to the CSF, the case is treated with more intrathecal therapy.
Whether testis is involved by leukemia cells in boys
Minimal residual disease as described below. This is an important risk factor.
Minimal residual disease and ALL
Minimal residual disease (MRD) is a term used when there are so few leukemia cells in the bone marrow that they cannot be seen under a microscope.
Highly sensitive tests can detect 1 leukemia cell in 10,000–1 million normal cells in the bone marrow.
Children who have positive MRD (more than 1 cell in 10,000) after induction therapy are at the greatest risk of relapse. The timing of MRD measurement varies depending on the center.
Side effects of acute lymphoblastic leukemia treatment
Side effects are hard to predict. They depend on the medicine and how a person reacts to it. Different people can have different reactions to the same medicine.
Side effects can happen during any phase of ALL treatment. The first weeks of treatment are the most likely to produce serious side effects. There are treatments for these side effects.
About 98% of children with ALL in the United States go into remission within weeks after starting treatment.
More than 90% of children with ALL in the U.S. can be cured. Patients are considered cured after about 5 years in remission.
Survival rates for ALL patients in low-risk groups can be more than 95%.
If patients have a form of ALL that does not respond to treatment (refractory) or comes back after treatment (relapsed), the medical team will discuss treatment options.
Tips for Parents
Physician survivor of acute lymphoblastic leukemia helps others.
Support for patients with acute lymphoblastic leukemia treatment
Patients may have to miss some school during treatment. The treatment center, school, parents, and student can work together to help the student keep up with school as much as possible.
Late effects of acute lymphoblastic leukemia treatment
Some ALL patients may have late effects. A late effect is a health problem that occurs months or years after treatment has ended.
Cancer patients should continue to be followed by their treatment center care team and/or a primary care provider after cancer treatment. Late effects can often be treated or, in some cases, prevented.
Different treatments may have different late effects. Not all patients will have late effects. Patients who had the exact same treatment may experience different late effects.
Chemotherapy treats cancer using medicines that work by interfering with cells as they divide. Learn more about chemo and how to prepare your child for it.
