Leukemia is a type of cancer that affects the blood. The two most common types in children are acute lymphoblastic leukemia and acute myelogenous leukemia.
In a person with leukemia, blood cells are released into the bloodstream before they are fully formed, so there are fewer healthy blood cells in the body.
Below, we describe the types of childhood leukemia, the symptoms, and the treatments. We then look at when to contact a doctor, what questions to ask, and where to find support.
Leukemia occurs when bone marrow releases new blood cells into the bloodstream before they are fully mature.
These immature blood cells do not function as they should, and eventually, the number of immature cells overtakes the number of healthy ones.
Leukemia can affect red and white blood cells and platelets.
The bone marrow produces stem cells. A blood stem cell can become a myeloid stem cell or a lymphoid stem cell.
Lymphoid stem cells become white blood cells. Myeloid stem cells can become:
- red blood cells
- white blood cells
Most childhood leukemias are acute, meaning that they progress quickly and need treatment as soon as possible.
Acute lymphoblastic leukemia
Acute lymphoblastic leukemia (ALL) is the most common type in children, accounting for 75% of childhood leukemia cases.
It affects cells called lymphocytes, a type of white blood cell.
In a person with ALL, the bone marrow releases a large number of underdeveloped white blood cells called blast cells. As the number of these increases, the number of red blood cells and platelets decreases.
There are two subtypes of ALL: B-cell and T-cell.
In most childhood cases of ALL, the cancer develops in the early forms of B-cells. The other type, T-cell ALL, typically affects older children.
Research from 2020 reports that the majority of people diagnosed with ALL are under 18 and typically between 2 and 10 years old.
The American Cancer Society report that children under 5 years old have the highest risk of developing ALL and that this risk slowly declines until a person reaches their mid-20s.
The outlook for ALL depends on the subtype, the person’s age, and factors specific to each person.
Acute myelogenous leukemia
Myeloid leukemias account for approximately 20% of childhood leukemia cases, and most myeloid leukemias are acute.
Acute myelogenous leukemia (AML) affects white blood cells other than the lymphocytes. It may also affect red blood cells and platelets.
AML can begin in:
- myeloblasts, which turn into white blood cells called granulocytes
- monoblasts, which turn into white blood cells called monocytes and macrophages
- erythroblasts, which turn into red blood cells
- megakaryoblasts, which turn into bone marrow cells called megakaryocytes
Juvenile myelomonocytic leukemia (JMML) accounts for approximately 1–2% of leukemia cases in children.
This rare type is neither acute nor chronic. JMML begins in the myeloid cells, and it typically affects children younger than 2 years.
Symptoms can include:
- pale skin
- a fever
- a cough
- easy bleeding or bruising
- a rash
- an enlarged spleen
- an enlarged liver
- enlarged lymph nodes
- difficulty breathing
The symptoms of leukemia may be nonspecific — similar to those of other common childhood illnesses.
A doctor will ask how long the child has been experiencing the symptoms, which can include:
- weight and appetite loss
- gum swelling, pain, and bleeding
- swollen lymph nodes
- swelling in the face and arms
- extreme fatigue and weakness
- bone and joint pain
- difficulty breathing
Children may experience specific symptoms depending on the type of blood cell that the leukemia is affecting.
A low number of red blood cells can cause:
- pale skin
- dizziness or lightheadedness
- shortness of breath
A low number of healthy white blood cells can cause infections or a fever with no other sign of an infection.
A low platelet count can cause:
- easy bleeding
- easy bruising
- frequent or severe nosebleeds
- bleeding gums
Various factors can increase a child’s risk of leukemia, and most are not preventable.
Genetic risk factors
The following genetic conditions can increase the risk of leukemia:
- Down syndrome
- Li-Fraumeni syndrome
- Wiskott-Aldrich syndrome
- Bloom syndrome
- Shwachman-Diamond syndrome
Also, having a sibling with leukemia may increase the risk of developing it.
Environmental risk factors
These can include exposure to:
If a child has symptoms that might indicate leukemia, a doctor may perform or request:
- a physical exam
- blood tests
- a bone marrow aspiration
- a biopsy
- a lumbar puncture, or spinal tap
- a lymph node biopsy
- imaging tests, such as CT and MRI scans
A bone marrow aspiration involves using a syringe to take a liquid sample of bone marrow cells. The doctor may give the child a drug that allows them to sleep through this test.
Questions to ask
During the diagnostic process, a person might ask:
- Which tests will be needed?
- Who will perform these tests?
- Where will they be performed?
- What will these tests entail?
- How and when will the results come in?
- Who can explain the results?
- What happens next?
The doctor may recommend a variety of treatments for childhood leukemia, and the best option depends on a range of factors specific to each person.
The treatment usually consists of two phases. The first aims to kill the leukemia cells in the child’s bone marrow, and the second aims to prevent the cancer from coming back.
The child may need:
- Chemotherapy: This involves using a mixture of drugs to kill the leukemia cells. It may come as injections, drips, or tablets.
- Targeted drugs: These are designed to only kill the leukemia cells without damaging healthy cells.
- Immunotherapy: This medication helps the body attack and destroy the leukemia cells.
- Stem cell transplant: This involves destroying the bone marrow and replacing the stem cells through a transplant.
- Radiation: This involves using high-energy rays to kill leukemia cells.
Questions to ask
Before or during treatment, a person might ask the doctor:
- Which type or combination of treatments they recommend, and why?
- What is the goal of each treatment?
- What other types will the child need?
- What are the side effects, and how can they be reduced?
- Will any vitamins or special diets help?
- How soon should the treatment begin?
- What can be done to prepare for it?
- What notes should be kept during the treatment?
- What are the next steps?
Questions to ask after the treatment might include:
- When will the child start to feel better?
- What is the schedule for aftercare and follow-up appointments?
- What tests are needed after treatment, and how often?
- What long-term health effects are expected?
- What are the chances that the leukemia will return?
- Which symptoms might arise?
- If symptoms develop, who should be called?
Children who have undergone leukemia treatments require follow-up care, as the treatments often cause late effects.
These can develop in anyone who has received treatment for cancer, and they may not arise for months or years after the treatment has ended.
Treatments that can cause late effects include:
- a stem cell transplant
- radiation therapy
These complications may affect:
- the function of organs and tissues
- development and growth
- psychological adjustments, possibly involving mood, feelings, and behaviors
- learning, memory, and thinking skills
- the risk of developing a second form of cancer
The late effects that may come can also depend on the type of treatment and the form of leukemia.
Because many leukemia symptoms can also indicate other issues, it can be hard to know when to contact a doctor.
Overall, it is best to seek medical advice if a child shows symptoms or behaviors that are not normal for them.
If a child has received a leukemia diagnosis, the effects can extend to parents, other family members, caregivers, and friends.
A person can find support and additional resources from:
The following organizations based in the United Kingdom also provide support and guidance:
- Children with Cancer UK
- Great Ormond Street Children’s Hospital
- CLIC Sargent
- Childhood Cancer Parents Alliance (CCPA)
Childhood leukemia can affect mental health, as well as physical health.
According to the American Cancer Society, most children with leukemia have no known risk factors. There is no way to prevent leukemia from developing.
Because there are very few lifestyle-related or environmental causes of childhood leukemia, it is very unlikely that a caregiver can do anything to help prevent the disease.
A child’s outlook depends on the type of leukemia. It is important to keep in mind that current estimates do not take into account recent advances in technology and medicine.
For example, the most recent 5-year survival rate estimates reflect the experiences of children who received their diagnoses and treatments more than 5 years ago.
The American Cancer Society report that the 5-year survival rate for children with ALL is 90%. The same rate for children with AML is 65–70%.
Childhood leukemia is typically acute, which means that it develops quickly. As a result, a person should contact a doctor if they notice any of the symptoms.
The most common type of childhood leukemia is ALL, representing 3 out of 4 leukemia cases in children.
Treatment may include a combination of chemotherapy, targeted drugs, immunotherapy, stem cell transplants, surgery, and radiation.
The prognosis depends on the type of leukemia and the child’s age.
This diagnosis can affect mental as well as physical health, and the effects can extend to caregivers, family members, and friends. Many different resources are available for support.