Leukemia is a cancerous growth of white blood cells. Types of leukemia are based on the two general types of white blood cells and whether the leukemia develops acutely or more slowly.
Four main types of leukemia are acute myelogenous leukemia, acute lymphocytic leukemia, chronic myelogenous leukemia, and chronic lymphocytic leukemia.
Acute leukemia can affect any person of any age. But, acute lymphocytic leukemia is generally found in children and young adults.
Acute myelogenous leukemia is more commonly found in adults, primarily ages 30 to 50.
Chronic myelogenous leukemia usually affects middle-aged adults, and chronic lymphocytic leukemia affects the elderly.
Risk factors for leukemia include exposure to radiation and chemicals such as benzene and petrochemicals, smoking cigarettes, and chromosome abnormalities such as Down's syndrome.
Individuals may have no symptoms or may complain of any of the following: fatigue, generally feeling ill (malaise), loss of appetite, easy bruising, bleeding from the gums or elsewhere, weight loss, shortness of breath, bone pain, abdominal pain, and/or night sweats.
Physical exam may reveal enlarged lymph nodes, enlarged liver and/or spleen, large or pinpoint bruises, gum enlargement, and fever. The individual may appear pale if anemia is present.
Tests: A complete blood count (CBC) with differential will show either a high or low white blood cell count, low platelets, and/or low hemoglobin/hematocrit (an anemia). The blood smear will usually reveal abnormal-appearing cells. A bone marrow biopsy is the definitive test and will show the presence and type of leukemia.
Blood clotting studies and blood chemistries may also be done. A lumbar puncture might be done to evaluate possible central nervous system involvement.
Treatment is based on the type of leukemia diagnosed.
Acute leukemia is treated with high dose chemotherapy to reduce the elevated white blood cell count.
A bone marrow transplant is considered for individuals whose leukemia is likely to return.
Chronic leukemias are often treated with chemotherapy to control the white blood cell count.
Alpha-interferon is a less common treatment.
Bone marrow transplant is being increasingly employed to treat the acute leukemias and chronic myelogenous leukemia.
Acute lymphocytic leukemia: Decadron (Dexamethasone), Rheumatrex (Methotrexate)
Chronic lymphocytic leukemia: Leukeran (Chlorambucil), Cytoxan (Cyclophosphamide)
Acute myelogenous leukemia: Vepesid (Etoposide)
Chronic myelogenous leukemia: Isotretinoin, Hydrea (Hydroxyurea)
Complications of leukemia can include bleeding, infection, and fatigue. Chemotherapy has its own side effects, such as nausea, vomiting, diarrhea, and a weakened immune system.
With present day treatments, the old distinctions of "acute" and "chronic" do not necessarily mean worse or better prognosis. Individuals with acute leukemia are often cured, while those with chronic lymphocytic leukemia are not cured despite a long survival rate of seven to fifteen years. The outcome is based on the stage of the disease and the treatment chosen. The progress of chronic myelogenous leukemia may be arrested in those individuals who respond to alpha-interferon. A bone marrow transplant may cure leukemia.
Various infections can elevate the white blood cell count. A malignant lymphoma can cause an elevated lymphocyte count. Anemia and low platelet count can result from many other conditions, including replacement of the bone marrow by "solid tumors."
Hematologist, medical oncologist, pathologist and radiation oncologist.