Chronic leukemia is a slowly progressing cancer that starts in blood-forming tissue and causes the production of abnormal blood cells. There are two main types: chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML), both of which primarily affect adults. Most people with CML have a gene mutation (change) called the Philadelphia chromosome. The cause of CLL is not known; however, some of the risk factors for the disease include having a family history of the disease and being middle-aged or older, male, or Caucasian.
Leukemia is cancer that starts in blood-forming tissue and causes large numbers of blood cells to be produced and enter the bloodstream. Each year, about 29,000 adults and 2,000 children in the United States are diagnosed with leukemia. Leukemia is either chronic (gets worse slowly) or acute (gets worse quickly). In early stages of chronic leukemia, the abnormal blood cells can still do their work, and people with chronic leukemia may not have any symptoms of the cancer. However, as the cancer slowly progresses, symptoms of chronic leukemia will appear as the number of leukemia cells in the blood rises.
Blood cells form in the bone marrow. Bone marrow is the soft material in the center of most bones. Immature blood cells are called stem cells and blasts. Most blood cells mature in the bone marrow and then move into the blood vessels. Blood flowing through the blood vessels and heart is called the peripheral blood.
In people with chronic leukemia, the bone marrow produces abnormal white blood cells, which are leukemia cells. At first, leukemia cells function almost normally. However, in time, they may crowd out normal white blood cells, red blood cells, and platelets, which makes it hard for blood to do its work. This may result in infection, anemia, and easy bleeding.