Pediatric Leukemia

Leukemia is cancer of the blood and develops in the bone marrow. When a child has leukemia, the bone marrow, for an unknown reason, begins to make white blood cells that do not mature correctly, but continue to reproduce themselves.  The body can regulate the production of cells by sending signals when to stop. With leukemia, these cells do not respond to the signals to stop and reproduce.

These abnormal cells reproduce very quickly and do not function as healthy white blood cells to help fight infection. When the immature white blood cells begin to crowd out  healthy cells in the bone marrow, the child experiences the symptoms of leukemia (i.e., infections, anemia, bleeding).

Types of childhood leukemia

Leukemia is the most common form of cancer in childhood. It affects approximately 3,800 children each year in the US, accounting for about 30 percent of childhood cancers. Leukemias are generally classified into acute (rapidly developing) and chronic (slowly developing) forms.  In children, approximately 98% of leukemias are acute.

Acute childhood leukemias are also categorized as acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), depending on whether specific white blood cells called lymphocytes (or myelocytes), which are linked to immune defenses, are involved. Although slow growing chronic myelogenous leukemia (CML) may also be seen in children, it is quite rare in this population, accounting for fewer than 50 cases of childhood leukemia per year in the US.

ALL is the type of leukemia that most commonly affects children, most often between the ages of 2 and 8 years, with a peak incidence at 4 years of age. In the US, approximately 60% of children with leukemia have ALL, and about 38% have AML.  AML generally occurs by the age of 2 years, and is not often seen in older children until the teenage years. AML is the most common type of acute leukemia in adults.

What causes leukemia in children?

With the exception of specific inherited syndromes, little is known about the causes of childhood leukemia. The inherited syndromes which are associated with a higher risk of developing leukemia include: Li-Fraumeni syndrome, Down syndrome, Kleinfelter syndrome, neurofibromatosis, ataxia telangectasia, and Franconi’s anemia. Children who have received prior radiation or chemotherapy for other types of cancer, or who are receiving drugs to suppress their immune systems after organ transplants are also at higher risk for leukemia.

The immune system plays an important role in protecting the body from diseases, and possibly cancer. An alteration or defect in the immune system may increase the risk for developing leukemia. Factors such as exposure to certain viruses, environmental factors, chemical exposures, and various infections have been associated with damage to the immune system.

The majority of childhood leukemias are believed to arise from acquired genetic diseases, ie noninherited mutations in the genes of growing blood cells. These gene mutations and chromosome abnormalities occur randomly and unpredictably. There is currently no effective way to prevent most types of leukemia.

What are the symptoms of leukemia in children?

Because leukemia is cancer of the blood-forming tissue called the bone marrow, the initial symptoms are often related to irregular bone marrow function. The bone marrow is responsible for storing and producing about 95 percent of the body’s blood cells, including the red blood cells, white blood cells, and platelets.

When leukemia occurs, the abnormal white blood cells (blasts) begin to reproduce very rapidly and begin crowding out and competing for nutrients and space with the other healthy cells. The following are the most common symptoms of leukemia. However, each child may experience symptoms differently.

  • anemia

    When red blood cells are unable to be produced because of the crowding in the marrow, anemia is present. With anemia, the child may appear tired, pale, and may breathe faster to compensate for the decrease in oxygen carrying capacity. The number of red blood cells on a blood count will be below normal.

  • bleeding and/or bruising

    When platelets are unable to be produced because of the crowding in the marrow, bleeding can occur and the child may begin to bruise more easily. Petechia are tiny red dots often seen on the skin of a child with low number of platelets. Petechia are very small blood vessels that have “leaked” or bled. The number of platelets on a blood count will be below normal. Thrombocytopenia is the term used for a decreased number of platelets.

  • recurrent infections

    Although there may be an unusually high number of white blood cells, these white blood cells are immature and do not fight infection. The child with leukemia often shows symptoms of an infection such as fever, runny nose, and cough.

  • Bone and joint pain


    Pain in bones and joints is another common symptom of leukemia. This pain is usually a result of the bone marrow being overcrowded and “full.”

  • abdominal distress

    Abdominal pain may also be a symptom of leukemia. Leukemia cells can collect in the kidney, liver, and spleen, causing enlargement of these organs. Pain in the abdomen may cause a child to have loss of appetite and weight loss.

  • swollen lymph nodes

    The child may also have swelling in the lymph nodes under the arms, in the groin, chest, and in the neck. Lymph nodes are responsible for filtering the blood. Leukemia cells may collect in the nodes, causing swelling.

  • difficulty breathing (dyspnea)

    With T-cell ALL, these leukemia cells tend to clump together around the thymus. This mass of cells present in the middle of the chest can cause pain and difficulty breathing (dyspnea). Wheezing, coughing, and/or painful breathing requires immediate medical attention.

With acute leukemia (ALL or AML), these symptoms may occur suddenly in a matter of days or weeks. With chronic leukemia (CML), these symptoms may develop slowly over months to years.

It is important to understand that the symptoms of leukemia may resemble other blood disorders or medical problems. These are common symptoms of the disease, but do not include all possible symptoms. Children may experience symptoms differently. A physician should always be consulted
for a diagnosis.

What are the various stages of medical treatment for pediatric leukemia

The various stages in the treatment of childhood leukemia include the following:

  • induction – a combination of chemotherapy and/or radiation and medications given to stop the process of abnormal cells being made in the bone marrow. Remission is the goal in this stage of treatment. Remission means the leukemia cells are no longer being made. This phase may last approximately one month and can be repeated if the goal is not achieved.
  • intensification or consolidation - continued treatment even though leukemia cells may not be visible. The leukemia cells may not be visible in a blood test or bone marrow examination, but it is possible that the cells are still present in the body.
  • maintenance – the stage that maintains leukemia-free bone marrow by continuing less intense chemotherapy for a longer duration. This phase can last months to several years. Regular visits to your child’s physician are required in order to determine response to treatment, detect any recurrent disease, and manage any side effects of the treatment.
  • relapse – may occur even with aggressive therapy. Relapse is when the bone marrow begins making abnormal cells again. Relapse can occur during any of the stages of treatment, or may occur months or years after treatment has ended.

The Pediatric Leukemia Treatment Team

Children with leukemia should have their treatment coordinated by a multi-disciplinary team of health care professionals with expertise in treating childhood leukemia and other diseases of the Blood.  Treatment should be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The treatment team may include the following specialists:

Because cancer in children is rare, taking part in a clinical trial should be considered. Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

Long-term outlook for a child with leukemia:

Prognosis greatly depends on:

  • the extent of the disease.
  • initial response to treatment.
  • genetics.
  • age and overall health of the child.
  • the child’s tolerance of specific medications, procedures, or therapies.
  • new developments in treatment.

As with any cancer, prognosis and long-term survival can vary greatly from child to child. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for the child diagnosed with leukemia.

Significantly, more children than ever are surviving childhood cancer. Over the last 30 years, survival into adulthood increased from 30 percent to 80 percent. There are new and better drugs and methods to help children deal with the side effects of treatment. And children who have had cancer now have a better quality of life throughout childhood and into adulthood; fewer long-term ill effects follow the treatment.

Information derived directly from National Cancer Institute, National Institutes of Health.  Please refer to http://www.cancer.gov/cancertopics/pdq/pediatrictreatment for source documentation and additional information.

Additional sources utilized: Stanford Medical Center and Children’s Hospital of Wisconsin