Leukemia is a cancer that originates in blood-forming (lymphoid) cells in the bone marrow or lymphatic system. Most often, the malignancy affects white blood cells and interferes with the immune system’s ability to fight infection.
Healthy white blood cells normally grow and divide in an orderly fashion as needed by the body. Leukemia occurs when these cells become damaged and acquire DNA mutations that cause them to function poorly and reproduce at a very rapid rate. The excess leukemic cells then build up in the bloodstream, eventually crowding out healthy blood cells and leaving the body susceptible to infection.
Common types of leukemia
There are four main types of leukemia. The cancer is classified based on the rate of its progression and the blood cells affected. Acute types of leukemia grow very quickly, while chronic types tend to develop gradually over time. Also, in chronic leukemia, the leukemic cells mature partly, but not completely, and therefore do not function as effectively as healthy blood cells.
Leukemia can arise in lymphoblasts, which mature into a specific type of white blood cell known as lymphocytes, or myeloid cells, which may become white blood cells, red blood cells or platelets.
Acute myeloid leukemia (AML)
The most common form of acute leukemia in adults, AML is a fast-growing cancer that develops in myeloid cells, causing those cells to mature into abnormal white blood cells. As the leukemia cells multiply, they can overwhelm the healthy cells in the bone marrow and blood and sometimes spread to other parts of the body.
Acute lymphocytic leukemia (ALL)
A fast-growing cancer that occurs more often in children than adults, ALL originates in lymphoblasts. As a result, the bone marrow produces an abundance of immature leukemic cells that do not develop into properly functioning lymphocytes.
Chronic myeloid leukemia (CML)
CML is relatively uncommon and typically affects older adults. Although the leukemic cells tend to grow faster and survive longer than healthy blood cells, CML doesn't completely interfere with the development of mature white blood cells, red blood cells or platelets. However, it usually causes healthy blood cell counts to be lower than normal.
Chronic lymphocytic leukemia (CLL)
CLL mainly affects older adults and accounts for approximately one-third of all leukemia cases. This slow-growing cancer originates in lymphoblasts in the bone marrow and blood.
Causes & risk factors
Within the medical community, the precise causes of leukemia are not yet fully understood. However, scientists have identified certain risk factors, such as advanced age and exposure to ionizing radiation, which may play a role in its development.
Researchers are also studying several genetic and environmental factors that have been linked to the cellular mutations that cause leukemia, including:
- Specific genetic conditions, such as Down syndrome and certain blood disorders
- Human T-lymphotropic virus (HTLV)
- Human immunodeficiency virus (HIV)
- Exposure to petrochemicals, such as benzene
- Alkylating chemotherapy agents administered to treat another type of cancer
- Smoking and other forms of tobacco use
- Use of certain hair dyes
Leukemia is the 10th most common cancer and accounts for 3.5% of new cancer cases diagnosed in the U.S. each year. While commonly thought of a disease that primarily affects children, the truth is that adults are diagnosed at a far greater rate. In fact, the age group most frequently diagnosed with leukemia is adults age 65 to 74.
Leukemia symptoms can vary based on the type and stage of the cancer. Also, because acute types of leukemia tend to progress much more quickly than chronic types, their symptoms generally appear earlier and worsen faster as well. Some warning signs include:
- Flu-like symptoms, including fever, chills and body aches
- Night sweats
- Overwhelming weakness or fatigue
- Loss of appetite
- Severe or recurrent infections
- Easy bleeding and bruising
- Frequent nosebleeds
- Tiny red skin spots (petechiae)
- Swollen lymph nodes
- Enlarged liver or spleen
- Unexplained weight loss
- Bone pain or tenderness
Moffitt's approach to treating leukemia
Moffitt Cancer Center is a high-volume cancer center, and the multispecialty team in our renowned Malignant Hematology Program has extensive experience in diagnosing and treating all types of leukemia, including relatively uncommon malignancies. We take an individualized approach to cancer treatment, determining the optimal course of action depending on the type and stage of the cancer as well as the patient’s unique characteristics and preferences.
Highly regarded for our commitment to leukemia research and our robust clinical trials program, Moffitt has been designated a Comprehensive Cancer Center by the National Cancer Institute. We offer a full range of targeted therapies for leukemia, including:
- Radiation therapy
- Bone marrow transplants
- Stem cell transplants
If you would like further information, you are welcome to talk with a leukemia specialist in the Malignant Hematology Program at Moffitt Cancer Center. To request an appointment, please call 1-888-663-3488 or complete our new patient registration form online.