Leukemia

Leukemia specialists recognize four types of the disease. Distinctions between acute and chronic stages of leukemia depend upon the number and ratio of lymphoblasts (immature leukocytes), erythrocytes, and thrombocytes (platelets). Acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) were diagnosed in 13,200 Americans in 1999, whereas chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) accounted for 12,300 more cases in the same year. Another 4,600 Americans were diagnosed with rare forms such as erythroleukemia (affecting red blood cells), hairy-cell leukemia (HCL) and monocytic leukemia. Patients with leukemia can experience thrombocytopenia (insufficient platelets), which causes internal bleeding and excessive bruising, anemia (insufficient erythrocytes), which results in weakness, pale complexion, and dizziness due to insufficient oxygen, and leukopenia (insufficient disease-fighting leukocytes), which allows recurrent fevers and infections.

Due to increased skills, new technologies, and greater public awareness, more leukemia cases are being diagnosed. Leukemia accounts for nearly one-third of all new cases of cancer in children, but most cases are diagnosed in adults. Five-year survival rates for most forms of leukemia have dramatically risen, from roughly 5% in the early 1960s to 38% by the mid-1970s and 1980s. After diagnosis, greater than 40% of all patients with leukemia now survive for at least five years.

Researchers suspect that genetic, behavioral, and especially environmental factors cause leukemia. Morbidity (sickness) and mortality (death) rates vary greatly by gender, race, ethnicity, geography, and socioeconomic class. Forms of ionizing radiation, such as what Japanese survivors of atomic bombing experienced, are implicated strongly in three major forms of leukemia, but nonionizing forms of radiation (present in electricity) have also been linked to leukemia's epidemiology, or disease patterns across time. Exposure to benzene, which occurs in petroleum, chemical, shoe, and rubber manufacturing, and in painting and printing, correlates strongly to leukemia, but its use has been banned in the United States since 1945, although it is used elsewhere. Long-term exposure to agricultural fertilizers and infectious agents associated with livestock, pesticides, and diesel fuel and exhaust, have all been suggested as risk factors for the development of leukemia.

Both improved and new therapies have greatly reduced morbidity and mortality from leukemia. The hormone erythropoietin, for example, helps oxygen-carrying erythrocytes to multiply, which might help to treat some leukemia-caused anemias. Standard treatment options range from chemotherapy to biological therapies, from surgery to radiation, from radiation and chemotherapy combined to marrow stem cell transplantation. Surgery can be used to remove swollen and enlarged lymph nodes Close up of bone marrow in chronic lymphocytic leukemia cells. © Biophoto Associates, Science Source/Photo Researchers. Reproduced by permission.

or organs such as the spleen that cause severely decreased platelets in the bone marrow and bloodstream. Drug therapy is usually the first option, and the ultimate goal is complete remission, in which no lymphoblasts are seen in the blood and bone marrow is normal. Biotherapy (immunotherapy) works with synthesized forms of naturally occurring substances in the body (interferon and interleukins) to disrupt the multiplication and spread of immature cells (lymphoblasts). Homeopathic remedies treat leukemia as a character trait, as the body's expression of an insult to the system. Due to earlier detection and improved therapies, leukemia is no longer considered a virtual death sentence, and many people remain in remission decades after treatment.