Douglas A. Nelson, MD, is a board-certified oncologist and hematologist who previously served for 13 years as a physician in the US Air Force.
Leukemia is a form of blood cancer that impedes the normal production of white blood cells in the bone marrow. In leukemia, abnormal cells crowd out healthy cells, affecting their ability to fight infection. There are four main types of the disease. Acute leukemias are the most common cancer in children, but in general, leukemia is more common in older adults.
While an exact cause of leukemia is unknown, risk factors include genetics, smoking, radiation, and environmental exposures. Signs and symptoms include frequent infections, anemia, bruising, and weight loss.
Extensive testing is needed to confirm a diagnosis of leukemia. Treatment is based on the type of disease and may include chemotherapy, a stem cell transplant, and other approaches.
The exact cause of leukemia is not known, but risk factors for the disease include some infections, exposures to radiation or to chemicals such as benzene and pesticides, previous chemotherapy treatment, and certain genetic conditions.
There are several different types of leukemia, and each has a different prognosis. When leukemia stays in remission for five years, some doctors consider that it has been cured. As of 2016, the overall five-year survival rate for all types of leukemia was 63.7%.
The role of genetics and family history varies according to the type of leukemia. For example, acute lymphoblastic leukemia (ALL) does not tend to run in families. With chronic lymphocytic leukemia (CLL), on the other hand, those with a first-degree family member who have had CLL have more than twice the risk of developing the disease themselves.
Symptoms can vary according to the type of leukemia, but may include unexplained fevers, abnormal bruising, anemia, swollen lymph nodes, frequent infections, abdominal pain, and bone and joint pain.
Several tests may be involved in diagnosing leukemia, including blood tests, a bone marrow biopsy, lumbar puncture, and flow cytometry. One of the most important tests in determining the specific type of leukemia is a peripheral smear, in which a blood sample is smeared on a slide with a dye and placed under a microscope. This allows for a detailed picture of the blood cells.
A group of cancers, including leukemia and lymphoma, that affect components of the blood. Leukemia interferes with the normal production of white blood cells in the bone marrow, while lymphoma is a disease of the lymphocytes present in lymphoid tissue.
A spongy substance that fills the center of certain bones in the body. Stem cells in the bone marrow produce red blood cells, white blood cells, and platelets. Bone marrow is key for fighting infections and helping blood to clot.
A procedure in which a patient’s own bone marrow is replaced with healthy bone marrow from a donor or from their own stored marrow. Bone marrow transplants are used to treat leukemia and other types of cancers.
A group of bone marrow diseases, also called myelodysplastic syndromes, that suggest an increased risk of developing acute myelogenous leukemia (AML). All preleukemias affect the production of healthy blood cells in the bone marrow.
Acute lymphoblastic leukemia (ALL) is a type of leukemia that affects immature lymphocytes, a type of white blood cell referred to as “blasts.” ALL is the most common cancer in children, although it can affect adults as well.
A slow-growing cancer that starts in the bone marrow. In 95% of cases, CLL develops in a type of white blood cell known as a B-lymphocyte. Chronic lymphocytic leukemia is the most common leukemia in adults.
A type of cancer that starts in the bone marrow, moves into the blood cells, and often metastasizes to other parts of the body including the liver, spleen, skin, brain, and spinal cord. AML more commonly affects adults over 65 and has a low five-year survival rate.
A relatively rare, slow-growing form of leukemia that starts in immature white blood cells known as myeloid cells. CML can affect people of all ages, but nearly 70% of cases occur in adults over 50.
A general term that encompasses all neoplastic diseases of the hematopoietic and lymphoid tissues. Diseases in this category include leukemia, lymphoma, and myeloma, each of which involves different types of blood cells.
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