Childhood Leukemia

What is Childhood Leukemia?
Leukemia is cancer of the white blood cells. It is the most common type of childhood cancer, affecting more than 3,500 children in the U.S. every year. When a child 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.

What're the types of Childhood Leukemia?
The two types of leukemia that most commonly affect children are: Acute lymphoblastic leukemia (ALL) ; Acute myelogenous leukemia (AML). In rare cases, chronic lymphocytic leukemia (CLL) and chronic myelogenous leukemia (CML) will occur in children. About 98% of Childhood leukemias are acute.

What is sign and Symptom of Childhood Leukemia?
Due to infection-fighting white blood cells are defective in children with leukemia, these children may experience increased episodes of fevers and infections. They may also 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 may also 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 may 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
• poor appetite

The ALL form of the disease most commonly occurs in younger children ages 2 to 8, with a peak incidence at age 4. But it can affect all age groups. In about 12% of children with AML and 6% of children with ALL, spread of leukemia to the brain causes headaches, seizures, balance problems, or abnormal vision. If ALL spreads to the lymph nodes inside the chest, the enlarged gland can crowd the trachea (windpipe) and important blood vessels, leading to breathing problems and interference with blood flow to and from the heart.

How to diagnose Childhood Leukemia?
It is very important both to diagnose childhood leukemia as early as possible and to determine what type of leukemia is present so that treatment can be tailored to provide the best chance of success. The exams and tests below are used to diagnose the disease, measure how advanced it may be, and to help determine what type of leukemia is present.

The child doctor will perform a physical examination to check for signs of infection, anemia, abnormal bleeding, and swollen lymph nodes. The doctor will also feel your child's abdomen to see if there is an enlarged liver or spleen. After this exam, the doctor will order a complete blood count to measure the numbers of white cells, red cells, and platelets in child's blood. A blood smear will also be examined under a microscope to check for certain specific types of abnormal blood cells that are typically seen in patients with leukemia. Blood chemistries will also be checked.

Then, depending on the results of child's physical exam and preliminary blood tests, need to diagnosis as following:
a bone marrow biopsy and aspiration, in which marrow samples are removed from the body (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 ;
a lumbar puncture (spinal tap), where a sample of spinal fluid is removed from the lower back and examined for evidence of abnormal cells. This will show whether the leukemia has spread to the central nervous system (brain and spinal cord) ;
Bone marrow or lymph node samples will be examined and additional testing will be done to determine the specific type of leukemia. In addition to these basic lab tests, cell evaluations are also generally done, including genetic studies to distinguish between specific types of leukemia, as well as certain features of the leukemia cells. Children will receive anesthesia or sedative medications for any painful procedures.

Childhood leukemia is diagnosed by taking a sample of bone marrow from the hip with a needle. A spinal tap is also performed to determine whether leukemia has affected the central nervous system. At the Children's Cancer Hospital, these procedures are performed under anesthesia for minimal discomfort to your child. Special doctors called hematopathologists use a full battery of laboratory tests to identify the leukemia type.

How to treatment Childhood Leukemia?
Certain features of a child's leukemia, such as age and initial white blood cell count, are used in determining the intensity of treatment needed to achieve the best chance for cure.

Chemotherapy, using drugs to kill cancer cells, is the most common treatment for pediatric leukemia. Chemotherapy to kill leukemia cells using strong anti-cancer drugs. Many children with all stages of leukemia benefit from clinical trials of new drugs and drug combinations that seek more effective treatments with minimal impact on quality of life.

For children whose leukemia has returned or has not responded to standard treatments, a bone marrow transplant may be required. Stem cells, which are immature blood cells, are taken from the bone marrow of the patient before cancer treatment (autologous), or from a donor whose marrow most closely matches allogeneic. Stem cells may also be collected from a newborn's umbilical cord and placenta and used for a cord blood transplant. These cells are used to replace diseased stem cells destroyed by cancer treatment, creating a new "blood factory" that will hopefully produce healthy, mature white blood cells.

Radiation therapy may be used when leukemia has affected the brain and central nervous system or is likely to spread to these areas. Beams of radiation are precisely aimed at the treatment area from outside the body.