Leukemia – Causes and Treatment of Leukemia
Leukemia is a cancer of blood-forming cells in the bone marrow. These deranged, immature cells accumulate in the blood and within organs of the body. They are not able to carry out the normal functions of blood cells. Normal blood contains 3 major groups of cells: white blood cells, red blood cells, and platelets. All 3 types of blood cells develop from one immature cell type, called blood/marrow stem cells, in a process called hematopoiesis.
In leukemia, your bone marrow produces a large number of abnormal white blood cells. They look different from normal blood cells and don’t function properly. Eventually, they block production of normal white blood cells, impairing your ability to fight off infection. Leukemia cells also crowd out other types of blood cells produced by the bone marrow, including red blood cells, which carry oxygen to tissues throughout your body, and platelets, which help form blood clots.
Causes of Leukemia
Acute leukemia: In acute leukemia, the abnormal blood cells are immature blood cells (blasts). They can’t carry out their normal work, and they multiply rapidly, so the disease worsens quickly. Acute leukemia requires aggressive, timely treatment.
Viruses: The human T-cell leukemia virus I (HTLV-I) is related to acute T-cell leukemia. This type of leukemia is well documented in parts of the Caribbean and Asia, but it is uncommon in the United States and Europe. Higher rates of leukemias also have been reported in workers who are exposed to animal viruses (e.g., butchers, slaughterhouse workers, veterinary practitioners).
Chronic leukemia: This type of leukemia involves more mature blood cells. These blood cells replicate or accumulate more slowly and can function normally for a period of time. Some forms of chronic leukemia produce no signs or symptoms and can go unnoticed or undiagnosed for years.
Genetics–Leukemia risk is increased 15-fold among children with Down’s syndrome, which is a genetically linked chromosomal abnormality (usually an extra copy of chromosome 21). Three rare inherited disorders—Fanconi’s anemia, Bloom’s syndrome, and ataxia telangiectasia—also have an increased risk for leukemia.
Treatment for Leukemia
Chemotherapy: Chemotherapy is the major form of treatment for leukemia. This treatment uses chemical agents to kill leukemia cells. Depending on the type of leukemia you have, you may receive a single drug or a combination of one or more drugs. These drugs may come in a pill form, or they may be injected directly into a vein.
Interferon Therapy: Interferons are a class of proteins that are released by virus-infected cells. They help normal cells to make antiviral proteins. Interferons also help the body to reduce leukemia cell proliferation (growth and reproduction), while strengthening the body’s immune response.
Kinase inhibitors: For most people with CML, the drug imatinib mesylate (Gleevec) is the first line of therapy. Imatinib mesylate is a type of cancer drug called a kinase inhibitor. It was specifically developed to inhibit the BCR-ABL protein, and it has proved effective in treating the early stages of chronic myelogenous leukemia. Several newer kinase inhibitors are in development.
Surgery is generally not used to treat leukemia. Occasionally, a person with leukemia that has spread to the spleen has the spleen removed. This is usually done only if the spleen is so large that it is causing problems for nearby organs.
Radiation therapy: Radiation therapy uses X-rays or other high-energy rays to damage leukemia cells and stop their growth. You may receive radiation in one specific area of your body where there is a collection of leukemia cells, or you may receive radiation directed at your whole body.