Leukemia is a type of blood cancer that begins in the bone marrow, where all blood cells form. It is the most common form of childhood cancer. Leukemia affects approximately 4,000 children each year in the U.S., accounting for about 35 percent of childhood cancers.
Leukemia begins when a single bone marrow cell fails to mature into a blood cell and becomes a leukemia cell. The leukemia cells multiply and eventually fill the bone marrow, crowding out the normal blood-forming cells. This makes it hard for normal cells to do their work of fighting infection, carrying oxygen and stopping bleeding.
As the abnormal cells circulate in the blood, leukemia can spread to other parts of the body such as the lymph nodes, spleen, liver and central nervous system, which includes the brain and spinal cord.
The exact cause of leukemia is not known. The majority of childhood leukemias are acquired diseases. This means that leukemia occurs by chance and is not inherited from a parent. Usually, children with leukemia do not have any known risk factors. Possible risk factors for leukemia include:
- Inherited immune system deficiencies
- Immunosuppressant medicines, such as those provided after organ transplant
- Down syndrome, a genetic condition affecting a child's physical and mental development
- Li-Fraumeni syndrome, a rare genetic condition that greatly increases the risk for cancer
Although every child experiences symptoms differently, the initial symptoms of leukemia are often related to irregular bone marrow function. Symptoms may seem to occur suddenly, developing in a matter of days or weeks. Some symptoms result from too many leukemia cells. Other symptoms result from leukemia cells crowding out normal cells.
Symptoms of leukemia include:
- Pain deep in the bones
- Swollen lymph nodes
- Difficulty breathing
- Broken bones
- Recurrent infections
Because symptoms of leukemia may resemble other blood disorders or medical problems, it is important to visit your child's primary care doctor if he or she is experiencing any of these symptoms.
The three types of leukemia that affect children most often are:
- Acute lymphoblastic leukemia (ALL). ALL is the most common type of leukemia in young children. "Acute" means the cells become cancerous in the early stage of development. Normal white blood cells fight infection. Lymphoblasts (cancer cells) do not mature correctly and cannot help fight infection. They crowd out other blood cells. The risk for developing ALL is highest in children younger than 5 years of age, but children of all ages and adults can develop ALL. Children respond better to treatment than adults with this type of leukemia.
- Acute myeloid leukemia (AML). AML is the second most common type of childhood leukemia. Normal myeloid cells develop into red blood cells, platelets or white blood cells. Acute myeloid leukemia affects the myeloid cells during early development. Although the abnormal cells are different in ALL and AML, the way in which cancerous cells crowd out healthy cells is similar.
- Chronic myeloid leukemia (CML). CML progresses slowly and is uncommon in children. “Chronic” means cells become cancerous later in development than cells in AML. CML cancerous cells in the marrow do not mature correctly and eventually crowd out healthy cells, similar to the way AML cells do. Almost all CML patients have a specific chromosome defect in the leukemia cells called the Philadelphia chromosome. It causes the uncontrolled growth of the leukemia cells.
Diagnosis of Leukemia
Pediatric cancer doctors at Riley at IU Health start with a complete medical history and physical examination of your child. The most common diagnostic tests for leukemia involve looking at samples of blood and bone marrow under a microscope. Further genetic and immunologic tests determine whether the cells are myeloid or lymphoid, which determines the type of leukemia.
Children with leukemia often require a spinal tap to test for leukemia around the brain and spine. This test looks for cancer cells in the cerebrospinal fluid (the liquid around the brain and spine).
Your child's doctor will first address symptoms such as anemia, bleeding and/or infection. Children often require blood and platelet transfusions. Your child's doctor may also use antibiotics to prevent and/or treat infections.
Chemotherapy is the key to curing leukemia. Other treatments may include radiation therapy to treat leukemia or to keep it from spreading and bone marrow transplant. Specific treatment depends on the type of leukemia:
- ALL. Children with ALL usually receive outpatient chemotherapy treatment. Depending on their condition, a child with this type of leukemia will require daily to weekly chemotherapy for the first six to 12 months. Then they receive monthly treatments for two or three years. Children who respond poorly to treatment, have a recurrence of leukemia or have rare specific genetic mutations found in their leukemia may receive a stem cell or bone marrow transplant.
- Chimeric Antigen Receptor (CAR) T-Cell Therapy. CAR T-cell therapy is an emerging form of cancer immunotherapy. Riley at IU Health is the only pediatric healthcare system in Indiana to offer CAR T-cell therapy to treat pediatric patients and young adults with acute lymphoblastic leukemia (ALL) and young adults with non-Hodgkin lymphoma.
- What is CAR T-Cell Therapy? This CAR T-cell therapy involves supercharging a patient’s T cells to recognize and attack cancer cells. T-cells are a kind of white blood cell that has the job of targeting and destroying bacteria, viruses, and cancer cells. However, with certain types of blood cancers, your T-cells may not be able to do their job properly. That’s where CAR T-cell therapy may help. It is used after failure of two other kinds of treatment. For this treatment, your child’s blood will be collected over the course of a few hours and passed through a machine that separates out some their T-cells. After your child’s T-cells are collected, they will be sent to a laboratory and modified to become CAR T-cells. Your child will undergo several days of low-dose conditioning chemotherapy to prepare their body for treatment. Your child’s CAR T-cells will then be infused back into your body to help recognize and attack your cancer cells. After the CAR-T cells are infused, your child will need to remain in the hospital for 2-4 weeks and will need to stay within 2 hours of Riley at IU Health for 4-8 weeks to monitor for side effects of treatment.
- AML. Children with acute myeloid leukemia need more intensive, hospital-based treatment for about six months. One third to one half of children with AML may benefit from having a stem cell or bone marrow transplant as part of their initial treatment.
- CML. Children with chronic myeloid leukemia receive outpatient chemotherapy using an oral medicine specific for CML. This medicine targets a specific enzyme in leukemia cells with the Philadelphia chromosome. Children often receive this medicine for life. Those who do not respond to chemotherapy may be candidates for treatment with a stem cell transplant
Key Points to Remember
Key Points to Remember
- Leukemia is a type of blood cancer that begins in the bone marrow, where all blood cells form.
- It is the most common form of childhood cancer.
- The majority of childhood leukemias are acquired diseases, not inherited from a parent.
- Acute lymphoblastic leukemia is the most common type of leukemia in young children.
- Chemotherapy is the key to curing leukemia
Support Services & Resources
Support Services & Resources
Learn more about leukemia at these recommended online resources:
Riley at IU Health offers a broad range of supportive services to make life better for families who choose us for their children's care.
In addition to our primary hospital location at the Academic Health Center in Indianapolis, IN, we have convenient locations to better serve our communities throughout the state.
IU Health North Hospital
Pediatric Cancer & Blood Diseases
11700 N Meridian St
Carmel, IN 46032