The term leukemia refers to cancers of the white blood cells (also called leukocytes
or WBCs). When someone has leukemia, large numbers of abnormal white blood cells are
produced in the bone marrow. These abnormal white cells crowd the bone marrow and
flood the bloodstream, but they cannot perform their proper role of protecting the
body against disease because they are defective.
As leukemia progresses, the cancer interferes with the body's production of other
types of blood cells, including red blood cells and platelets. This results in anemia (low numbers of red
cells) and bleeding problems, in addition to the increased risk of infection caused
by white cell abnormalities.
As a group, leukemias account for about 30% of all childhood cancers and affect
more than 3,000 American young people each year. Luckily, the chances for a cure
are very good with leukemia. With treatment, most children with leukemia will be free
of the disease without it coming back.
Types of Leukemia
In general, leukemias are classified into acute (rapidly developing)
and chronic (slowly developing) forms. In children, most leukemias
The ALL form of the disease most commonly occurs in younger children ages 2 to
8, but it can affect all age groups. AML can occur at any age, but it is somewhat
more common before the age of 2 and during the teenage years.
Although experts don't know exactly what causes leukemia, it seems that some types
of childhood leukemia may be linked to genetic or environmental factors.
Kids have a greater chance of developing ALL or AML if they have an identical twin
who was diagnosed with the illness at a young age. (Nonidentical twins and other siblings
of children with leukemia have a higher than average risk of developing this illness.)
Also, children who have inherited certain genetic problems — such as Li-Fraumeni
syndrome, Down syndrome,
ataxia telangectasia, or Fanconi's anemia — have a higher risk of developing
Children who have received prior radiation or chemotherapy
for other types of cancer also have a higher risk for leukemia, as do kids who
are receiving medical drugs to suppress their immune systems after organ transplants.
In most cases, neither parents nor kids have control over the factors that trigger
leukemia. Most leukemias arise from noninherited mutations (changes) in the genes
of growing blood cells. Because these errors occur randomly and unpredictably, there
is currently no effective way to prevent most types of leukemia.
To limit the risk of prenatal radiation exposure as a trigger for leukemia (especially
ALL), women who are pregnant or who suspect that they might be pregnant should always
inform their doctors before undergoing tests
or medical procedures that involve radiation (such as X-rays).
Because their infection-fighting white blood cells are defective, kids with leukemia
may have more viral or bacterial infections than usual. They also may become
anemic because leukemia affects the bone marrow's production of oxygen-carrying red
blood cells. This makes them appear pale, and they may become abnormally tired and
short of breath while playing.
Children with leukemia might bruise and bleed very easily, experience frequent
nosebleeds, or bleed
for an unusually long time after even a minor cut because leukemia destroys the bone
marrow's ability to produce clot-forming platelets.
Other symptoms of leukemia can include:
pain in the bones or joints, sometimes causing a limp
swollen lymph nodes (sometimes called swollen glands) in the neck, groin, or elsewhere
an abnormally tired feeling
fevers with no other symptoms
abdominal pain (caused by abnormal blood cells building up in organs like the
kidneys, liver, or spleen)
Occasionally, the spread of leukemia to the brain can cause headaches,
problems, or abnormal vision. If ALL spreads to the lymph nodes inside the chest,
the enlarged mass can crowd the trachea (windpipe) and important blood vessels,
leading to breathing problems, and interfere with blood flow to and from the heart.
To determine whether a child has leukemia, a doctor will do a physical
examination to check for signs of infection, anemia, abnormal bleeding, and swollen
lymph nodes. The doctor will also feel the child's abdomen to check the liver
and spleen because these organs can become enlarged by some childhood cancers.
The doctor also will take a medical history by asking about symptoms, past health,
the family's health history, medications the child is taking, allergies, and other
After this exam, the doctor will order a CBC
(complete blood count) to measure the numbers of white cells, red cells, and platelets
in the child's blood. A blood smear will be examined under a microscope to check for
certain specific types of abnormal blood cells usually seen in patients with leukemia.
Blood chemistries also will be checked.
Then, depending on the results of the physical exam and preliminary blood tests,
the child might need:
a bone marrow biopsy
and aspiration, in which marrow samples are removed (usually from the back of
the hip) for testing
a lymph node biopsy, in which lymph nodes are removed and examined under a microscope
to look for abnormal cells
imaging studies, such as X-rays, ultrasounds, CT scans, or MRIs
Besides these basic lab tests, cell evaluations might be done, including genetic
studies to distinguish between specific types of leukemia and certain features of
the leukemia cells. Kids will receive anesthesia or sedative medications for any painful
Regular checkups can spot early symptoms of leukemia in the relatively rare cases
where this cancer is linked to an inherited genetic problem, to prior cancer treatment,
or to the use of immunosuppressive drugs for organ transplants.
Kids who are diagnosed with leukemia are referred to a pediatric oncologist, a
specialist in childhood cancer, for evaluation, treatment, and close monitoring.
Treatment for leukemia usually is carried out by a team of specialists, including
nurses, social workers, psychologists, surgeons, and other health care professionals.
Certain patient features (such as age and initial white blood cell count) are used
to help doctors decide which type of treatment will provide the best chance for
Chemotherapy is the main treatment for childhood leukemia, although the dosages
and drug combinations may differ. Chemo can be given by mouth, into a vein, or into
the spinal fluid.
Intensive leukemia chemotherapy has certain side
effects, including hair loss, nausea and vomiting, and increased risk for
infection or bleeding in the short term, as well as other potential
health problems later. As a child is treated for leukemia, the cancer treatment
team will watch closely for those side effects and treat them as needed.
Other types of treatment include radiation
therapy (high-energy rays that kill cancer cells), targeted therapy (specific
drugs that identify and attack cancer cells without hurting normal cells), and stem cell transplants
(the introduction of healthy stem cells into the body).
With the proper treatment, the outlook for kids and teens who are diagnosed with
leukemia is quite good. Most childhood leukemias have very high remission rates, with
some up to 90% (remission means there is no longer evidence of cancer cells in the
body). Overall cure rates differ depending on the specific features of the disease.
And the majority of kids can be cured of the disease (meaning that they are in permanent