Chronic lymphocytic leukemia Overview
Chronic lymphocytic leukemia (CLL) is a type of cancer of the blood and bone marrow – the spongy tissue inside bones where blood cells are made.
The term “chronic” in chronic lymphocytic leukemia comes from the fact that it typically progresses more slowly than other types of leukemia. The term “lymphocytic” in chronic lymphocytic leukemia comes from the cells affected by the disease a group of white blood cells called lymphocytes, which help your body fight infection.
Chronic lymphocytic leukemia most commonly affects older adults. Chronic lymphocytic leukemia treatments can help control the disease.
What is leukemia?
Leukemia is a cancer that starts in the blood-forming cells of the bone marrow. When one of these cells changes and becomes a leukemia cell, it no longer matures normally. Often, it divides to make new cells faster than normal. Leukemia cells also don’t die when they should. This allows them to build up in the bone marrow, crowding out normal cells. At some point, leukemia cells leave the bone marrow and spill into the bloodstream, often causing the number of white blood cells in the blood to increase. Once in the blood, leukemia cells can spread to other organs, where they can prevent other cells in the body from functioning normally.
Leukemia is different from other types of cancer that start in organs like the lungs, colon, or breast and then spread to the bone marrow. Cancers that start elsewhere and then spread to the bone marrow are not leukemia.
Not all leukemias are the same. Knowing the specific type of leukemia helps doctors better predict each patient’s prognosis (outlook) and select the best treatment.
What is a chronic leukemia?
Whether leukemia is acute or chronic depends on whether most of the abnormal cells are immature (and are more like stem cells) or mature (and are like normal white blood cells).
In chronic leukemia, the cells can mature partly but not completely. These cells may look fairly normal, but they are not. They generally do not fight infection as well as normal white blood cells do. The leukemia cells survive longer than normal cells, and build up, crowding out normal cells in the bone marrow. Chronic leukemias can take a long time before they cause problems, and most people can live for many years. But chronic leukemias are generally harder to cure than acute leukemias.
What is a lymphocytic leukemia?
Whether leukemia is myeloid or lymphocytic depends on which bone marrow cells the cancer starts in.
Lymphocytic leukemias (also known as lymphoid or lymphoblastic leukemia) start in the cells that become lymphocytes. Lymphomas are also cancers that start in those cells. The main difference between lymphocytic leukemias and lymphomas is that in leukemia, the cancer cell is mainly in the bone marrow and blood, while in lymphoma it tends to be in lymph nodes and other tissues.
Signs and symptoms of Chronic lymphocytic leukemia
Patients with Chronic lymphocytic leukemia present with a wide range of symptoms and signs. Onset is insidious, and it is not unusual for Chronic lymphocytic leukemia to be discovered incidentally after a blood cell count is performed for another reason; 25-50% of patients will be asymptomatic at time of presentation.
Symptoms include the following:
- Enlarged lymph nodes, liver, or spleen
- Recurring infections
- Loss of appetite or early satiety
- Abnormal bruising (late-stage symptom)
- Night sweats
Causes of Chronic lymphocytic leukemia
The cause of Chronic lymphocytic leukemia is unknown. There is no link to radiation. It is not clear whether certain chemicals cause Chronic lymphocytic leukemia. But exposure to Agent Orange during the Vietnam War has been linked to a slight increased risk of developing Chronic lymphocytic leukemia.
Chronic lymphocytic leukemia usually affects older adults, especially those older than age 60. Persons under age 45 rarely get it. Chronic lymphocytic leukemia is more common in whites than in other ethnic groups. It is more common in men than in women. Some persons with Chronic lymphocytic leukemia have family members with the disease.
How common is it?
Each year in Australia around 1000 people are diagnosed with Chronic lymphocytic leukemia, making it the most common type of leukaemia. Generally, Chronic lymphocytic leukemia is a rare disease, accounting for 0.8% of all cancers diagnosed.
Who gets it?
The risk of developing Chronic lymphocytic leukemia increases with age. Almost 80 per cent of all new cases are diagnosed in people over the age of 60 years. Chronic lymphocytic leukemia is rare in people under 40. It occurs more frequently in men than in women.
Chronic Lymphocytic Leukemia Treatment
After chronic lymphocytic leukemia has been diagnosed, tests are done to find out how far the cancer has spread in the blood and bone marrow.
Staging is the process used to find out how far the cancer has spread. It is important to know the stage of the disease in order to plan the best treatment. The following tests may be used in the staging process:
- Chest x-ray : An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body, such as the lymph nodes.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the brain and spinal cord. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- Blood chemistry studies : A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Antiglobulin test : A test in which a sample of blood is looked at under a microscope to find out if there are any antibodies on the surface of red blood cells or platelets. These antibodies may react with and destroy the red blood cells and platelets. This test is also called a Coombs test.
The following stages are used for chronic lymphocytic leukemia:
- Stage 0
In stage 0 chronic lymphocytic leukemia, there are too many lymphocytes in the blood, but there are no other signs or symptoms of leukemia. Stage 0 chronic lymphocytic leukemia is indolent (slow-growing).
- Stage I
In stage I chronic lymphocytic leukemia, there are too many lymphocytes in the blood and the lymph nodes are larger than normal.
- Stage II
In stage II chronic lymphocytic leukemia, there are too many lymphocytes in the blood, the liver or spleen is larger than normal, and the lymph nodes may be larger than normal.
- Stage III
In stage III chronic lymphocytic leukemia, there are too many lymphocytes in the blood and there are too few red blood cells. The lymph nodes, liver, or spleen may be larger than normal.
- Stage IV
In stage IV chronic lymphocytic leukemia, there are too many lymphocytes in the blood and too few platelets. The lymph nodes, liver, or spleen may be larger than normal and there may be too few red blood cells.