Facts About Childhood Leukemia

Leukemia is a cancer of the blood that affects white blood cells which are produced in the bone marrow. When someone has leukemia, large numbers of abnormal white blood cells are released into the blood stream. Because the cells are abnormal, they cannot work as they should to protect the body from disease.

Occurrence, risk factors and symptoms

Leukemia occurs in both children and adults. Chronic leukemia, which is slow growing, is more common in adults. Acute leukemia, which develops rapidly, is more common in children. The risk of a child developing leukemia is about 1 in 2000.

It accounts for approximately 75% of all diagnosed leukemias and 25% of all childhood cancers in the United States, with children aged 3-5 years most often diagnosed.

In most cases it is not known exactly what causes leukemia to develop but experts believe there are certain conditions that put a child at an increased risk for developing leukemia. These conditions include:

-          Having an identical twin diagnosed at an early age

-          Certain inherited genetic or immune system disorders

-          Exposures to high levels of radiation or chemotherapy due to treatment for a previous cancer

-          Having a history of taking, or currently taking drugs to suppress the immune system after an organ transplant

Symptoms of leukemia in children are due to the large number of abnormal cells in the blood stream and to interference with the production of other important blood cells in the bone marrow. Two important cells that are affected are the red blood cells and platelets. Red blood cells carry oxygen and iron to all tissues of the body.

The anemia can cause them to look pale, feel more tired than usual and in severe cases, be short of breath while playing or exercising. Platelet cells are important for clotting.  Impaired platelet function results in easy bruising and prolonged bleeding from even simple cuts.  Because cells of the immune system are also affected, children with leukemia are more often sick with colds and flu symptoms. Other symptoms of leukemia include:

-          Joint pain

-          Swollen lymph nodes

-          Poor appetite

-          Fevers

-          Abdominal pain

See Also: Interferon Treatment For Leukemia

Genetic abnormalities lead to childhood leukemia

It is well documented that childhood leukemia is a disease caused by a number of genetic chromosomal abnormalities. These abnormalities define the different types of leukemia and their prognosis for cure or remission. There is now evidence that chromosomal abnormalities are the first step in the development of leukemia and that this begins in the prenatal period during fetal development. Evidence to this effect comes from studies of twin infants diagnosed with ALL, children with similar types of ALL and the studies of newborn blood samples on archived Guthrie cards. Identifying the same abnormal gene on the Guthrie card as in the leukemia patient’s blood cells is very strong evidence that childhood leukemia is initiated during fetal development.

Treatment And Prognosis For Childhood Leukemia

Survival rates and prognosis

Since effective treatment began, the long-term survival rate for childhood leukemia has significantly increased. This is due in large part to a better understanding of the disease process, an improved ability of medical providers to predict a relapse, the ability to choose a therapy more appropriate to the type of leukemia being treated, and to improved treatment protocols. There are clinical indicators that can help to determine a prognosis for survival. The most prognostic indicators for long term survival are age, white blood cell count at the time of diagnosis, the type of underlying genetic mutation, the disease response to chemotherapy, and the level of ALL cells measured at different intervals during treatment. Age as a prognostic indicator for survival is pretty consistent.

Infants younger than six months have a very low survival rate. Statistics show that very young children and adults have much lower survival rates. Treatment outcomes for adults worsen with increasing age. As adults age they are more likely to have other health problems in addition to the ALL. Also, the most common form of leukemia in adults is Philadelphia chromosome-positive ALL. The incidence of this type of leukemia increases with age and the prognosis remains poor regardless of treatment type.

White blood cells, another prognostic indicator, have a reverse correlation with survival; increasing numbers of abnormal white blood cells corresponds with a lower survival rate. In one type of ALL, a high white blood cell count is linked with an increased risk for relapse of the leukemia in the central nervous system, resulting in brain damage, stroke and hemorrhage. Statistics reveal that children younger than one year and older than ten years, with a high white blood cell count, have a very low survival rate regardless of the type of treatment used. Also, children with early-stage disease have a higher survival rate than those with late-stage disease.

Treatment for childhood leukemia

Treatment for ALL involves multiple types of therapies. These include chemotherapy, radiation, steroids and stem cell therapy. Research of childhood leukemia has resulted in the treatment modifications that better target the cause of the leukemia, thereby improving long-term survival rates. One such modification is the use of radiation. It used to be that all children diagnosed with ALL received cranial irradiation. This was an attempt to prevent the spread of the leukemia into the brain and central nervous system. Cranial irradiation is extremely toxic to a child’s developing brain and causes significant neurological damage that persists throughout the child’s life. Instead, intrathecal injection of chemotherapeutic agents is now used to treat and prevent the spread of leukemia to the central nervous system. This appears to be effective and causes less long-term neurological problems. High energy radiation is still used to target tumors and prevent the spread of the cancer to other areas of the body.

There are different types of chemotherapy available and the choice will be determined by the type of cancer being treated. If the cancer is not responding to treatment, then stem cell therapy is another option. Stem cells are unique blood cells that can develop into different types of cells in the body. The stem cells are transplanted into the child’s blood using an intravenous catheter. To prepare for the stem cell transplant, the child’s bone marrow is destroyed using medications and radiation so that the stem cells can rebuild a healthy bone marrow.

See Also: Gene Therapy Beats Leukemia In Eight Days

Long-term prospects

There have been several studies that show that survivors of childhood leukemia are vulnerable to a number of medical problems later in life as a result of the therapy used to treat their leukemia. They have an increased risk of developing a second blood related malignancy, pediatric brain tumors or later in life, cardiac disease, stroke, and endocrine disorders. Psychological and cognitive issues can also occur as a result of the childhood leukemia experience. Some survivors will experience mood disturbances, behavioral problems and post-traumatic stress. People who are treated successfully for childhood leukemia are at a much higher risk for physical and psychological health problems and should have periodic health evaluations to assess for development of issues related to their cancer treatment that require further management.