Kids and Health Care: Leukemia
The term leukemia actually refers to several distinct cancers of the white blood cells (also called leukocytes or WBCs). Leukemia is worth considering because it's the most common type of cancer among people under 18 years of age. When a child has leukemia, large numbers of defective white blood cells are produced in the bone marrow. These abnormal white cells crowd the bone marrow and flood the bloodstream, but they can't perform their proper role of protecting the body against disease.
As leukemia progresses, it interferes with the body's production of other types of blood cells, including red blood cells and platelets. Initially, leukemia cells may appear only in the bone marrow and blood, but later they may spread elsewhere, including the lymph nodes, spleen, liver and brain.
Cases of leukemia are classified as either acute (rapidly developing) or chronic (slowly developing); almost all cases of childhood leukemia are acute. Childhood leukemias are further divided into acute lymphocytic leukemia (ALL) or acute nonlymphocytic leukemia (ANLL), depending on whether they involve specific white cells called lymphocytes.
ALL generally occurs in younger children ages 2 to 8, with a peak incidence at age 4; AML may be seen in infants during the first month of life, but then it becomes relatively rare until the teen years.
Children who have inherited certain genetic problems -- such as Down's syndrome, Kleinfelter syndrome and neurofibromatosis -- have a higher risk of developing leukemia, as do children who are receiving drugs to suppress their immune systems after organ transplants.
Most leukemias arise from noninherited mutations in the genes of growing blood cells. Because these errors occur randomly and unpredictably, there is no effective way to prevent most types of leukemia.
The most common medical treatment for leukemia is radiation therapy combined with bone-marrow transplant; in some cases, a doctor may opt for chemotherapy instead. The good news is that cancer specialists have gotten very good at treating leukemia with radiation.
The main side effect of the radiation therapy is that, in addition to wiping out the cancer, it almost always wipes out all of the patient's bone marrow. This is the reason that the bone marrow transplant becomes necessary. In some cases, bone marrow will be "harvested" from the patient in advance of the radiation therapy and replaced afterwards; in other cases, it will be harvested from a family member or other donor when it's needed.
The bone marrow transplant can be painful, time-consuming and expensive -- more so than the radiation itself. Until the mid-1990s, many managed care plans and some insurance companies refused coverage for radiation therapy and bone-marrow transplants because, they claimed, the procedures were "experimental." A series of high-profile lawsuits gutted this argument. Now, just about all plans cover radiation (or chemotherapy) for kids.
While cancer experts warn against looking for "cures," the prospects for a child with leukemia have improved dramatically in the last 20 years. By one estimate, 80 percent of children diagnosed with leukemia can expect to survive.
