Leukemia
All types of blood cells are produced by bone marrow. Bone marrow is
the spongy tissue inside the large bones of the body. The bone marrow
produces red blood cells (which carry oxygen and other materials to all
tissues of the body), white blood cells (which fight infection) and
platelets (which help blood to clot).
In leukemia, the process of bone marrow controlling the production of normal
cells breaks down. The bone marrow then begins producing large numbers of
abnormal cells of only one type, usually one of the white cells. These abnormal,
immature cells, called blasts, then flood the blood stream and lymph system, and
may invade vital organs such as the brain, testes, ovaries or skin.
Leukemia can be acute (progressing quickly with many immature blasts) or
chronic (progressing slowly with more mature-looking cancer cells). Acute
myeloid leukemia progresses quickly.
If your child has symptoms of leukemia, the doctor may order blood tests to
count the number of each of the different kinds of blood cells. If the results
of the blood tests are not normal, a bone marrow biopsy may be performed. During
this test, a needle is inserted into a bone in the hip and a small amount of
bone marrow is removed and examined, enabling the doctor to determine the type
of leukemia and the best treatment plan.
Childhood acute lymphoblastic leukemia (ALL)
Acute lymphoblastic leukemia (ALL) is the most common form of childhood
cancer. It affects lymphocytes, a class of white blood cells. Leukemic cells
accumulate in the bone marrow, replace normal blood cells and spread to the
liver, spleen, lymph nodes, central nervous system, kidneys and gonads.
This cancer affects about 2,000 children each year in the United States and
usually occurs between the ages of three and five.
Close to 98 percent of children with newly diagnosed acute lymphoblastic
leukemia attain complete remission (absence of leukemic cells) in four to six
weeks. With modern therapy, 70 to 75 percent of children may be cured. If a
child does not relapse within three years after therapy is complete, the
likelihood of the child never relapsing is excellent.
Treatment for this disease usually involves chemotherapy. Chemotherapy is
given to the child until a complete remission is achieved. Additional drugs may
also be used to kill any malignant cells remaining after chemotherapy. All
chemotherapy is stopped after two to three years of treatment. In very high risk
cases or relapses, bone marrow transplants may be an option for treatment.
Childhood acute myeloid leukemia (AML)
Childhood acute myeloid leukemia (AML) is a cancer of the blood-forming
tissue, primarily the bone marrow and lymph nodes. AML is also referred to as
acute nonlymphocytic leukemia or acute myelogenous leukemia, and is divided into
several subtypes. It is less common than acute lymphocytic leukemia.
The primary treatment for AML is chemotherapy, sometimes followed by a bone
marrow transplant. Radiation therapy may also be used in certain cases.
Biological therapy is being studied in clinical trials as a treatment for AML.
There are two or three phases of treatment for AML. The first phase,
remission induction therapy, uses chemotherapy to kill as many leukemia cells as
possible and cause it to go into remission. Once the leukemia goes into
remission, postremission therapy is given. The purpose of postremission therapy
is to kill any remaining leukemia cells. Postremission therapy is divided into
two phases, postremission consolidation and postremission intensification. Your
child may receive either or both phases of postremission therapy.
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