by: Ossama Mazagri & Gene Bailey
Leukemia is a malignant progressive disease in which the bone marrow and other blood-forming organs produce increased numbers of immature or abnormal leukocytes. These suppress the production of normal blood cells, leading to anemia and other symptoms. Scientists don't understand the exact causes of leukemia. It seems to develop from a combination of genetic and environmental factors. In general, leukemia is thought to occur when some blood cells acquire mutations in their DNA — the instructions inside each cell that guide its action. Or other changes in the cells that have yet to be fully understood could contribute to leukemia. Certain abnormalities cause the cell to grow and divide more rapidly and to continue living when normal cells would die. Over time, these abnormal cells can crowd out healthy blood cells in the bone marrow, leading to fewer healthy blood cells and causing the signs and symptoms of leukemia. Leukemia symptoms vary, depending on the type of leukemia. Common leukemia signs and symptoms include: fever or chills, persistent fatigue, weakness, frequent or severe infections, losing weight without trying, swollen lymph nodes, enlarged liver or spleen, easy bleeding or bruising, recurrent nosebleeds, tiny red spots in your skin (petechiae), excessive sweating, especially at night, and bone pain or tenderness. Doctors may find chronic leukemia in a routine blood test, before symptoms begin. If this happens, or if you have signs or symptoms that suggest leukemia, you may undergo the following diagnostic exams: Your doctor will look for physical signs of leukemia, such as pale skin from anemia and swelling of your lymph nodes, liver and spleen. By looking at a sample of your blood, your doctor can determine if you have abnormal levels of white blood cells or platelets — which may suggest leukemia. Your doctor may recommend a procedure to remove a sample of bone marrow from your hipbone. The bone marrow is removed using a long, thin needle. The sample is sent to a laboratory to look for leukemia cells. Specialized tests of your leukemia cells may reveal certain characteristics that are used to determine your treatment options. You may undergo additional tests to confirm the diagnosis and to determine the type of leukemia and its extent in your body. Certain types of leukemia are classified into stages, indicating the severity of the disease. Your leukemia's stage helps your doctor determine a treatment plan. The number of new cases of leukemia was 13.0 per 100,000 men and women per year. The number of deaths was 7.0 per 100,000 men and women per year. These rates are age-adjusted and based on 2007-2011 cases and deaths. Approximately 1.4 percent of men and women will be diagnosed with leukemia at some point during their lifetime, based on 2009-2011 data. In 2011, there were an estimated 302,800 people living with leukemia in the United States. Factors that may increase your risk of developing some types of leukemia include: People who've had certain types of chemotherapy and radiation therapy for other cancers have an increased risk of developing certain types of leukemia. Genetic abnormalities seem to play a role in the development of leukemia. Certain genetic disorders, such as Down syndrome, are associated with increased risk of leukemia. People who have been diagnosed with certain blood disorders, such as myelodysplastic syndromes, may have an increased risk of leukemia. People exposed to very high levels of radiation, such as survivors of a nuclear reactor accident, have an increased risk of developing leukemia. Exposure to certain chemicals, such as benzene — which is found in gasoline and is used by the chemical industry — also is linked to increased risk of some kinds of leukemia. Smoking cigarettes increases the risk of acute myelogenous leukemia. If members of your family have been diagnosed with leukemia, your risk of the disease may be increased. However, most people with known risk factors don't get leukemia. And many people with leukemia have none of these risk factors. Leukemia is not a single disease. Instead, the term leukemia refers to a number of related cancers that start in the blood-forming cells of the bone marrow. There are both acute and chronic forms of leukemia, each with many subtypes that vary in their response to treatment. In addition, children with leukemia have special needs that are best met by care in pediatric cancer centers. Such centers have trained medical professionals whose sole purpose is to address the unique concerns of children.
Leukemia treatment plans often are personalized and geared toward each individual patient. In general, there are five major approaches to the treatment of leukemia: chemotherapy to kill leukemia cells using strong anti-cancer drugs; interferon therapy to slow the reproduction of leukemia cells and promote the immune system's anti-leukemia activity; radiation therapy to kill cancer cells by exposure to high-energy radiation; stem cell transplantation (SCT) to enable treatment with high doses of chemotherapy and radiation therapy; and surgery to remove an enlarged spleen or to install a venous access device (large plastic tube) to give medications and withdraw blood samples. Oncologists administer these treatments in a variety of combinations. Each method has its advantages and drawbacks. It usually is worthwhile to get a second opinion about treatment before entering into a specific program; in some instances, a second opinion may be required by the patient's insurance company. For example, stem cell transplantation (SCT) is very costly and entails a long stay in the hospital. Some insurance companies still consider this to be an "experimental" procedure and will not pay for SCT-related expenses. The treatment of leukemia depends on a number of factors. The most important of these are the histopathologic (diseased tissue) type of leukemia, its stage, and certain prognostic features, such as the patient's age and overall health.