Chronic lymphocytic leukemia is usually a slowly progressing disease in which mature-appearing lymphocytes (a type of white blood cell) become cancerous and gradually replace normal cells in lymph nodes.
People may have no symptoms, or they may have general symptoms such as tiredness, fever, night sweats, and unintended weight loss.
People may also have enlarged lymph nodes and a sense of abdominal fullness due to enlargement of the spleen.
Blood tests are needed for diagnosis.
Treatment includes chemotherapy drugs, monoclonal antibodies, and sometimes radiation therapy.
(See also Overview of Leukemia)
More than three fourths of the people who have chronic lymphocytic leukemia (CLL) are older than 60, and the disease is extremely rare in children. CLL is the most common type of leukemia in North America and Europe. It is rare in Japan and Southeast Asia and in people of Japanese and Southeast Asian descent living in the United States, which suggests that genetics plays some role in its development.
The number of cancerous, mature-appearing lymphocytes increases first in the blood, bone marrow, and lymph nodes. Cancerous lymphocytes then spread to the liver and spleen, both of which begin to enlarge.
In the bone marrow, cancerous lymphocytes may crowd out normal blood-producing cells, resulting in a decreased number of one or more of the following:
Red blood cells, which carry oxygen in the bloodstream
White blood cells, which help defend the body against infection
Platelets, small cell-like particles that help in the clotting process
Cancerous lymphocytes do not function like normal lymphocytes, which produce proteins (antibodies) that help fight infections. The smaller number of healthy lymphocytes that remain are not always able to produce enough antibodies, so infection is likely. Also, the immune system, which ordinarily defends the body against foreign organisms and substances, sometimes becomes misguided, reacting to and destroying normal tissues. This misguided immune activity can result in the destruction of red blood cells, neutrophils, or platelets.
CLL can sometimes transform into an aggressive cancer called lymphoma. This type of transformation, called Richter's transformation, happens in 2 to 10 percent of cases.
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Symptoms of CLL
In early stages of CLL, most people have no symptoms, and the disease is diagnosed only because of an increased white blood cell count. Later symptoms may include
Enlarged lymph nodes
Fatigue
Loss of appetite
Weight loss
Night sweats
Shortness of breath when exercising
A sense of abdominal fullness resulting from an enlarged spleen
As CLL progresses, people may appear pale and bruise easily. Bacterial, viral, and fungal infections may occur late in the course of the disease as the bone marrow produces fewer healthy white blood cells to fight infection.
Diagnosis of CLL
Blood tests
Sometimes CLL is discovered accidentally when blood counts ordered for some other reason show an increased number of lymphocytes. Specialized blood tests (called flow cytometry and immunophenotyping) to characterize the abnormal lymphocytes can be done on the cells in the blood. Blood tests also may show that the numbers of red blood cells, platelets, and antibodies are low.
A bone marrow evaluation is not necessary for the diagnosis of CLL but, if done, often shows an increased number of lymphocytes.
Treatment of CLL
Chemotherapy
Immunotherapy
Because CLL progresses slowly, many people do not need treatment for years, Doctors usually wait to begin treatment until one or more of the following occur
The number of lymphocytes begins to increase and cause symptoms
The lymph nodes, liver, or spleen enlarge
The number of red blood cells or platelets decreases
Drug treatment of CLL
Drugs, including chemotherapy and immunotherapy (such as monoclonal antibodies) drugs, help relieve symptoms and shrink enlarged lymph nodes and spleen but do not cure the disease. Treatment can control CLL for many years and can often be used again with success when the leukemia regrows.
stem cell transplantation can be done in people who have relapsed.
Treatment of CLL symptoms
Anemia is treated with blood transfusions and occasionally with injections of erythropoietin or darbepoietin (drugs that stimulate red blood cell formation). A low platelet count may cause bleeding and is treated with platelet transfusions. Infections are treated with antimicrobials. Radiation therapy is used to shrink enlarged lymph nodes or an enlarged liver or spleen if the enlargement is causing discomfort and chemotherapy is ineffective.
Prognosis for CLL
Usually CLL progresses slowly. Doctors determine how far the disease has progressed (staging) to predict the survival time. Staging is based on several factors, including the
Number of lymphocytes in the blood
Number of lymphocytes in the bone marrow
Size of the spleen
Size of the liver
Number of red blood cells in the blood
Number of platelets in the blood
People who are in the early stages of CLL often survive 10 to 20 years or longer after the diagnosis is made and usually do not need treatment in the early stages. People who have a low number of red blood cells (anemia) or a low number of platelets (thrombocytopenia) need more immediate treatment and have a less favorable prognosis. Usually, death occurs because the bone marrow can no longer produce a sufficient number of normal cells to carry oxygen, fight infections, and prevent bleeding.
For reasons probably related to changes in the immune system, people who have CLL are more likely to develop other cancers, such as skin cancers or lung cancers. CLL can also transform into a more aggressive type of cancer of the lymphatic system (lymphoma).
More Information
The following English-language resource may be useful. Please note that the MANUAL is not responsible for the content of this resource.
Leukemia & Lymphoma Society: What is CLL: General information on many aspects of chronic lymphocytic leukemia, including diagnosis, treatment options, and research findings
