Childhood Leukemia

What is Childhood Leukemia? Leukemia is the most common childhood cancer, affecting more than 3,500 children in the U.S. every year. Leukemia affects two types of white blood cells which are responsible for protecting the body from disease: lymphocytes and granulocytes. Leukemias that affect lymphocytes are known as "lymphocytic" and those that affect granulocytes are called "myeloid" or "myelogenous" leukemias. Leukemia is also classified as either acute or chronic. In acute leukemia, white blood cells are released from the bone marrow into the bloodstream before they mature, where they reproduce rapidly. In chronic leukemias, the blood cells are a bit more mature and multiply at a much slower rate.

Symptoms of Leukemia Fatigue or weakness Flu-like symptoms Lost appetite; unexplained weight loss Night sweats Frequent infections Easy bruising or bleeding Swollen or tender lymph nodes Anemia Tiny red spots under the skin (petechiae) Bone or joint pain

Childhood leukemia types include: Acute Lymphoblastic Leukemia (ALL)is the most common leukemia seen in children, accounting for 75% of all pediatric cases. ALL occurs in two distinct age groups: infants under three years of age, and young teenagers. Acute Myelogenous Leukemia (AML)strikes both children and adults. About 20% of childhood leukemia cases are AML. Juvenile Myelomonocytic Leukemia (JMML)is a rare disease that mostly strikes children under four years of age. About 15% of JMML cases occur in children with neurofibromatosis type 1, a genetic disorder that is also treated at the Children's Cancer Hospital.

Diagnosis
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 M. D. Anderson, 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. M. D. Anderson has the most comprehensive childhood leukemia service in the United States, with the expertise to make an accurate diagnosis and choose the most appropriate treatment.

Treatment
Chemotherapy, using drugs to kill cancer cells, is the most common treatment for pediatric leukemia. In recent years, several promising new drugs studied at M. D. Anderson have since become standard treatments. 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.

Chemotherapy is done in three stages:

Inductionis the first cycle of treatment, killing enough leukemia cells to put the patient in remission, where the disease can no longer be detected in the blood or bone marrow. This phase lasts about a month, and your child may be hospitalized the entire time.

Consolidationtreatment lasts at least four months and as long as eight months. Although the patient is in remission, thousands, even millions, of leukemia cells may remain. Combinations of chemotherapy drugs are used to reduce the number of remaining cancer cells.

Maintenance involves less frequent treatments

For children whose leukemia has returned or has not responded to standard treatments, a bone marrow transplantmay 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 the patient (allogeneic). 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 therapymay 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.

M. D. Anderson's Leukemia treatment team includes experts in all forms of cancer therapy. They collaborate on each case to decide the best possible treatment for every child.

Clinical Trials for Childhood Leukemia
The most innovative treatments for childhood leukemias are offered as part of clinical trials, which are closely monitored studies to test the safety and effectiveness of new treatments.