Childhood leukemia is the most common form of cancer in children. Leukemia affects roughly 3,800 children each year in the United States and accounts for about 30 percent of childhood cancers. Leukemia is most common in children between ages 2 and 6, but can occur at any age.
Leukemia is cancer of the blood. The cancer cells grow in bone marrow — the soft, spongy center of bones — and then enter the blood. Bone marrow produces three main blood cell types.
Leukemia happens when the bone marrow makes abnormal cells that don’t mature or work properly. Most often, the abnormal cells are white blood cells, or leukocytes. The abnormal leukocytes overproduce and do not respond to signals telling them to stop growing. These cells do not function normally, and therefore cannot help the body perform needed functions, like fighting infections.
The most common types of childhood leukemia are acute lymphoblastic leukemia (also known as ALL or acute lymphocytic leukemia) and acute myeloid leukemia (also called AML or acute myelogenous leukemia). Both are acute cancers, meaning they grow quickly.
ALL is the most common type of childhood leukemia, accounting for about 75 percent of childhood leukemia cases. ALL occurs in lymphocytes, which are white blood cells that specialize in recognizing and responding to infections. There are two types of lymphocytes, B cells and T cells, and leukemia can occur in either.
Lymphocytes are a key component of the immune system. They identify and kill or neutralize foreign particles in the body, such as viruses or bacteria. However, in leukemia, the bone marrow produces too many immature lymphocytes (or lymphoblasts) that do not mature properly and thus cannot fight infection. These lymphoblasts then crowd the bone marrow so fewer healthy cells are produced.
AML is the second most common blood cancer in children, and it affects 500 children each year in the United States. AML starts in myeloid cells, which normally form non-lymphocyte white blood cells, red blood cells, or platelets. There are a number of different subtypes of AML, each of which begins in myeloid cells.
There are also other, less common childhood leukemias. These include:
Scientists don’t know the exact cause of leukemia in children. Leukemia may be the result of mutations in the genes of bone marrow cells. These mutations are sporadic, meaning they happen by chance and may occur early in the child’s life. In rare circumstances, a child may inherit a condition that increases the risk of leukemia.
Additionally, children who receive chemotherapy or radiation to treat other types of cancer have an increased risk of developing leukemia later in life. Children with certain genetic conditions, such as Down syndrome, are also more likely to develop leukemia.
Unlike in adults, leukemia in children is not strongly associated with environmental or lifestyle risk factors.
There is no way to prevent leukemia in children.
The signs and symptoms of leukemia in children can vary greatly. Many of the symptoms of leukemia can be caused by other conditions. Nevertheless, if your child has any of these symptoms, it is important for your child to see a doctor so the cause can be determined and treated. Symptoms of leukemia may include:
In both forms of acute leukemia (ALL or AML), these symptoms can have a sudden onset in a matter of days or weeks. In chronic leukemia (CML), these symptoms may develop slowly over the course of months or years.
The symptoms listed above are common symptoms of leukemia, but do not include all possible symptoms. It is important to note that these symptoms may appear to resemble other medical problems, such as blood disorders.
If you notice your child is experiencing symptoms of leukemia, it is essential that they be seen by their pediatrician. It is also important to discuss being referred to a pediatric oncologist, who specializes in treating children with cancer. You may be referred to a pediatric cancer center. These cancer centers offer specialized care and clinical trials run by the Children’s Oncology Group (COG), which is supported by the National Cancer Institute (NCI).
If leukemia is suspected, your child will undergo diagnostic tests. These may include blood tests, bone marrow aspiration, bone marrow biopsy, lumbar puncture (spinal tap), lymph node biopsy, and genetic testing.
Your child may first receive blood transfusions and antibiotics to restore blood counts and fight infections soon after the diagnosis of leukemia. Treatment will depend on the type of leukemia and other factors. Possible treatments include chemotherapy, radiation therapy, stem cell transplants, targeted therapy, and clinical trials.
It is important to seek emotional support for your child, yourself, and other family members. Speaking with a therapist, attending in-person support groups, or connecting with others on MyLeukemiaTeam can help your entire family face cancer.
On MyLeukemiaTeam, the social network and online support group for those living with leukemia and their caregivers, members talk about a range of personal experiences. A number of members have children with leukemia.
Have you and your family faced childhood leukemia? Share your experience in the comments below or on MyLeukemiaTeam.