Leukemia Facts
Leukemia begins in the bone marrow and multiplies just like other cells. Lymphocytic or lymphoblastic leukemias come from bone marrow cells that form lymphocytes—white blood cells that are part of the immune system. Different kinds of lymphocytes do different things:
Myelogenous or myeloid leukemias occur in bone marrow cells that normally become red cells, some white cells, and platelets.
Leukemia cells grow and survive better than normal cells and, over time, crowd out normal cells. The rate at which leukemia progresses and how the cells replace the normal blood and marrow cells are different with each type of leukemia.
When acute, leukemia quickly prevents a large proportion of early blood cells from maturing. In chronic leukemia, more healthy blood cells get a chance to mature, so symptoms usually come on more gradually, and they are less severe at first.
Read more about
Original acute myelogenous leukemia (AML) cells and acute lymphocytic leukemia (ALL) cells come from immature blood cells and make about a trillion leukemia cells that don’t work like normal cells that crowd out normal cells in the bone marrow. Red cell counts drop and the patient becomes anemic.
In chronic myelogenous leukemia (CML), the leukemia cell that starts the disease still makes red and white blood cells and platelets, which work almost like normal cells. Red cell counts are usually less than normal, but many white cells and platelets are still being produced. Even though the white cells are nearly normal in how they work, their counts are high and they continue to rise, which can cause serious problems if the patient does not get treatment. If untreated, the white cell count can rise so high that blood flow slows down and anemia becomes severe.
In chronic lymphocytic leukemia (CLL), the leukemia cell that starts the disease makes too many non-functioning lymphocytes that replace normal cells in the bone marrow and lymph nodes, interfering with the normal lymphocytes so a person’s immune response become weakened. The high number of leukemia cells in the marrow may crowd out normal blood-forming cells and lead to a low red cell count. A very high number of leukemia cells building up in the marrow also can lead to low neutrophil and platelet counts.
Unlike the other three types of leukemia, some patients with CLL may have disease that does not progress for a long time. Some people with CLL have such slight changes that they remain in good health and do not need treatment for long periods of time. Most patients require treatment at the time of diagnosis or soon after.
There aren’t any real risk factors for most leukemias. Some people who may develop AML have received chemotherapy or radiation therapy for another form of cancer, including lymphoma, have Down syndrome or other genetic disease. Other risk factors seem to include exposure to benzene or tobacco smoke.
Leukemia symptoms begin like many other more common and less severe illnesses. People diagnosed with acute leukemia have experienced:
- Extreme tiredness
- Shortness of breath during physical activity
- Pale skin
- Mild fever or night sweats
- Slow healing of cuts and excess bleeding
- Bruises for no clear reason
- Pinhead-size red spots under the skin
- Aches in bones or joints
- Low white cell counts, especially monocytes or neutrophils
People diagnosed with CLL or CML may not have any symptoms however as they often come on gradually. Many learn of their diagnosis after a regular check-up and blood test. Enlarged lymph nodes in the neck, armpit, or groin often cause people to seek medical attention. When symptoms do appear, people with CML complain of feeling tired and short of breath, night sweats, and weight loss.
If you are concerned about persistent symptoms such as a low-grade fever, unexplained weight loss, tiredness, or shortness of breath see a health-care provider.
A complete blood count (CBC) is used to diagnose leukemia. This blood test may show high or low levels of white cells and show leukemic cells in the blood. Bone marrow tests (aspiration and biopsy) are often done to confirm the diagnosis and to look for chromosome abnormalities. These tests identify the leukemia cell-type. A complete blood exam and a number of other tests are used to diagnose the type of leukemia. These tests can be repeated after treatment begins to measure how well the treatment is working.