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Alternative Names: Chronic lymphoid leukemia.
Chronic Lymphocytic Leukemia (CLL) is a type of cancer that starts from white blood cells (lymphocytes) in the bone marrow, from where it invades the blood. Leukemia cells tend to build up in the body over time, but in many cases people don't have any symptoms for at least a few years. In time, it can also invade other parts of the body, including the lymph nodes, liver, and spleen. Compared to other types of leukemia, CLL usually grows slowly.
Leukemia is different from other types of cancer that start in organs such as 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.
Doctors have found that there seem to be 2 different kinds of CLL: - One kind of CLL grows very slowly and rarely needs to be treated. People with this kind of CLL survive an average of 15 years or more.
- The other kind of CLL grows faster and is a more serious disease. People with this form of CLL survive an average of about 8 years.
The leukemia cells from these 2 types look alike, but new lab tests can tell the difference between them.
Incidence; Causes & Development; Risk Factors
Each year, nearly 7,000 people in the United States learn that they have Chronic Lymphocytic Leukemia (CLL). The disease is very uncommon in individuals under 45 years of age. At the time of diagnosis, 95% of patients are over age 50 and the incidence of the disease increases dramatically thereafter.
CLL results from an acquired (not inherited) injury to the DNA of a single cell in the bone marrow. This injury is not present at birth. Scientists do not yet understand what produces this change in the DNA of CLL patients.
This change in the cell's DNA confers a growth and survival advantage on the cell, which becomes abnormal and malignant (leukemic). The result of this injury is the uncontrolled growth of lymphocytic cells in the marrow leading invariably to an increase in the concentration of lymphocytes in the blood. The leukemic cells that accumulate in the marrow in CLL do not impede normal blood cell production as profoundly as in the case of acute lymphocytic leukemia. This important distinction from acute leukemia accounts for the less severe early course of the disease.
Unlike the other three major types of leukemia, Chronic Lymphocytic Leukemia is not associated with high-dose radiation or benzene exposures. First-degree relatives of patients with the disease have about a threefold greater likelihood of getting the disease than other people. This should be put into perspective, however. For example, the 60-year-old sibling or offspring of a patient with chronic lymphocytic leukemia would have three chances in 10,000 of developing the disease compared to the one chance in 10,000 for a 60-year-old person without a family history of the disease.
Signs & Symptoms
The symptoms of chronic lymphocytic leukemia usually develop gradually. Patients tire more easily and may feel short of breath when physically active. They may lose weight. They may experience frequent infections of the skin, lungs, kidneys or other sites.
Diagnosis & Tests
Early in the disease, chronic lymphocytic leukemia may have little effect on a person's well-being. The disease may be discovered after finding an abnormal blood count during the course of a routine medical examination or while the patient is under care for an unrelated condition. The report of an elevated white blood cell count is the most common clue that leads a physician to consider the diagnosis of chronic lymphocytic leukemia. These large numbers of leukemic lymphocytes (white cells) can collect in the lymphatic system and the lymph nodes may become enlarged.
To diagnose the disease, the blood and, in most cases, the marrow cells must be examined. The white cell count invariably increases in the blood. A bone marrow examination will also show a marked increase in the proportion of lymphocytes in the marrow, often accompanied by some decrease in the normal marrow cells. Low platelet counts and low red cell counts (anemia) may be present, but are usually only slightly decreased in the early stage of the illness.
The pattern of the lymphocytes in the biopsy of the marrow can be one useful factor in determining the probable rate of progression of the disease. In addition, a sample of marrow is examined to determine if there is an abnormality of chromosomes. The examination of marrow cells to determine if an abnormality of chromosomes is present is referred to as a cytogenetics analysis.
Depending on the place in lymphocytic cell development in which the malignant transformation occurs, the leukemic cells may be principally B cells, T cells, or NK cells. Most patients have a B cell type of leukemia. A minority have T or NK cell types. These distinctions may be accounted for by the malignant transformation occurring after the common lymphocyte has differentiated into one of the three types of lymphocytes. The malignant event (mutation of DNA) would, therefore, occur at the point, or after, the early specialized lymphocytes were formed.
Determining the immunophenotype of the lymphocytes in the blood or marrow is important. This distinguishes whether the lymphocytes that accumulate are derived from a malignant transformation of a lymphocyte in the B cell developmental pathway or the T cell developmental pathway. The T cell type of disease, called T cell chronic lymphocytic leukemia, is very infrequent. When it occurs, it may affect the skin, nervous system and lymph nodes more often and is more rapidly progressive than is the B cell type. Immunophenotyping also permits an assessment of whether the lymphocytes in the blood are derived from a single malignant cell (whether they are monoclonal or not). The test for clonality is important because it distinguishes leukemia from the very infrequent increase in the blood lymphocytes in adults that is not the result of a malignant transformation characteristic of cancer.
Another very important test that is performed is the measurement of the concentration of gamma globulins (immunoglobulins) in the blood. Immunoglobulins are proteins called antibodies that the B cells of healthy individuals make to protect themselves from infection. They are often deficient in persons with chronic lymphocytic leukemia. The leukemic B lymphocytes do not make protective antibodies effectively. At the same time, the leukemia also acts to prevent residual normal lymphocytes from doing so. This inability to make antibodies efficiently makes CLL patients susceptible to infections.
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Signs, symptoms & indicators of Chronic Lymphocytic Leukemia (CLL):
Conditions that suggest Chronic Lymphocytic Leukemia (CLL):
Chronic Lymphocytic Leukemia (CLL) suggests the following may be present:
Recommendations and treatments for Chronic Lymphocytic Leukemia (CLL):
KEY | | Weak or unproven link |  | | Strong or generally accepted link |  | | Proven definite or direct link |  | | Likely to help |
GLOSSARY
Acute
An illness or symptom of sudden onset, which generally has a short duration.
Anemia (Anaemia, Anemias)
A condition resulting from an unusually low number of red blood cells or too little hemoglobin in the red blood cells. The most common type is iron-deficiency anemia in which the red blood cells are reduced in size and number, and hemoglobin levels are low. Clinical symptoms include shortness of breath, lethargy and heart palpitations.
Antibody (Antibodies)
A type of serum protein (globulin) synthesized by white blood cells of the lymphoid type in response to an antigenic (foreign substance) stimulus. Antibodies are complex substances formed to neutralize or destroy these antigens in the blood. Antibody activity normally fights infection but can be damaging in allergies and a group of diseases that are called autoimmune diseases.
Biopsy
Removal of a sample of tissue from a living being for diagnosis. A pathologist later uses a microscope to look for certain features, such as cancer cells, in the sample. A fine-needle aspiration biopsy involves inserting a thin needle to remove a small amount of tissue, sometimes using CT or ultrasound to guide the needle. A core biopsy involves obtaining a sample of tissue with a thick needle or by inserting a thin, lighted tube (laparoscope) into a small incision in the abdomen. Another biopsy method is to remove tissue during an operation.
Bone Marrow
The soft inner part of the bones, where new blood cells are made.
Cancer
Refers to the various types of malignant neoplasms that contain cells growing out of control and invading adjacent tissues, which may metastasize to distant tissues.
Chronic (Chronicity)
Usually referring to chronic illness: Illness extending over a long period of time.
Colon (Colonic)
The part of the large intestine that extends to the rectum. The colon takes the contents of the small intestine, moving them to the rectum by contracting.
DNA
Deoxyribonucleic acid, the large molecule that is the main carrier of genetic information in cells. DNA is found mainly in the chromosomes of cells.
Hodgkin's Disease (Hodgkin's)
Cancer of the lymphatic system and lymph nodes.
Kidneys (Kidney, Renal)
Bean-shaped organs, each about the size of a fist. They are located near the middle of the back, just below the rib cage. The kidneys are sophisticated reprocessing machines, each day handling about 50 gallons of blood to sift out about half a gallon of waste products and extra water. The waste and extra water become urine, which flows to the bladder through tubes called ureters. The actual filtering occurs in tiny units inside the kidneys called nephrons. Every kidney has about a million nephrons. In a nephron, a glomerulus -- which is a tiny blood vessel, or capillary -- intertwines with a tiny urine-collecting tube called a tubule. A complicated chemical exchange takes place, as waste materials and water leave your blood and enter your urinary system. The kidneys recycle chemicals such as sodium, phosphorus, and potassium and thus regulate their levels. Renal: Pertaining to the kidneys.
Leukemia
Cancer of the lymph glands and bone marrow resulting in overproduction of white blood cells (related to Hodgkin's disease).
Liver (Hepatic)
The largest and one of the most complex organs of the body, the liver is responsible for much of the metabolism of fats, proteins and carbohydrates. It is the site of much of the body's detoxification. It is connected very closely with digestion and the regulation of blood sugar, among many other functions. Found behind the ribs on the right side of the abdomen, it has many important functions such as removing harmful material from the blood, making enzymes and bile that help digest food, and converting food into substances needed for life and growth. Hepatic: Pertaining to the liver.
Lung (Lungs, Pulmonary)
Organ of the body, located in the chest cavity which is designed to bring oxygen from the air into the blood stream, while also expelling carbon dioxide and other waste gases out of the body. Pulmonary: Related to the lungs.
Lymph Nodes (Axillary Nodes, Inguinal Nodes, Lymph Gland, Lymph Glands, Lymph Node, Lymphatic)
Small, bean-shaped nodes at various points throughout the body that function to filter the lymph fluid and attempt to destroy the microorganisms and abnormal cells which collect there. The most common locations are the neck (both sides and front), armpit (axillary) and groin (inguinal), but also under the jaw and behind the ears. Swollen or painful lymph nodes generally result from localized or systemic infection, abscess formation, or malignancy. Other causes of enlarged lymph nodes are extremely rare. Physical examination for lymph nodes includes pressing on them to check for size, texture, warmth, tenderness and mobility. Most lymph nodes can not be felt until they become swollen, and then will only be tender when pressed or massaged. A lymph node that is painful even without touching indicates greater swelling. Lymph nodes can usually be distinguished from other growths because they generally feel small, smooth, round or oval-shaped and somewhat mobile when attempts are made to push them sideways. Because less fat covers the lymph nodes in children, they are easier to feel, even when they are not busy filtering germs or making antibodies. Childrens' nodes enlarge faster, get bigger in response to an infection and stay swollen longer than an adult's. Also known (incorrectly) as lymph glands.
Lymphatic System
A network of vessels which collect fluid from the tissues of the body and return it to the blood. Lymphatic fluid (also called lymph) is rich in white blood cells that fight infection and an important part of the body's immune system.
Lymphocyte
A type of white blood cell found in lymph, blood, and other specialized tissue such as bone marrow and tonsils, constituting between 22 and 28 percent of all white blood cells in the blood of a normal adult human being. B- and T-lymphocytes are crucial components of the immune system. The B-lymphocytes are primarily responsible for antibody production. The T-lymphocytes are involved in the direct attack against living organisms. The helper T-lymphocyte, a subtype, is the main cell infected and destroyed by the AIDS virus.
Lymphoma (Lymphomas)
Any tumor of the lymphatic tissues.
Malignant (Cancerous)
Dangerous. Mainly used to describe a cancerous growth -- when used this way, it means the growth is cancerous and predisposed to spreading.
Natural Killer Cells (NK, NK Cells)
An important first line of defense against newly arising malignant cells and cells infected with viruses, bacteria, and protozoa. They form a distinct group of lymphocytes with no immunological memory and are independent of the adaptive immune system. Natural Killer Cells constitute 5 to 16% of the total lymphocyte population. Their specific function is to kill infected and cancerous cells.
Nervous System
A system in the body that is comprised of the brain, spinal cord, nerves, ganglia and parts of the receptor organs that receive and interpret stimuli and transmit impulses to effector organs.
Platelets (Platelet)
Cells that help the blood to clot.
Protein (Proteins)
Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.
Selenium
An essential element involved primarily in enzymes that are antioxidants. Three selenium- containing enzymes are antioxidant peroxidases and a fourth selenium-containing enzyme is involved in thyroid hormone production. The prostate contains a selenium-containing protein and semen contains relatively large amounts of selenium. Clinical studies show that selenium is important in lowering the risk of several types of cancers. In combination with Vitamin E, selenium aids the production of antibodies and helps maintain a healthy heart. It also aids in the function of the pancreas, provides elasticity to tissues and helps cells defend themselves against damage from oxidation.
Serum
The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.
Spleen (Splenectomy)
The largest organ of the lymphatic system in the body, located between the stomach and the diaphragm (the muscle below the lungs which provides the motion for breathing). It destroys old red blood cells, produces lymphocytes and plasma cells, and stores blood. It also has other as yet unknown functions. A splenectomy is the surgical removal of the spleen.
White Blood Cell (WBC, White Blood Cells)
A blood cell that does not contain hemoglobin: a blood corpuscle responsible for maintaining the body's immune surveillance system against invasion by foreign substances such as viruses or bacteria. White cells become specifically programmed against foreign invaders and work to inactivate and rid the body of a foreign substance. White blood cells are composed primarily of neutrophils, monocytes and lymphocytes. Lymphocytes are either T-cells or B-cells. T-cells (CD3 cells) are divided into T-helper (CD4 cells) and T-suppressor/cytotoxic (CD8 cells) cells.
Last updated: Nov 14, 2009
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