What Is Chronic Lymphocytic Leukemia?
Chronic lymphocytic
leukemia (also known as
CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). Also known as chronic lymphoblastic leukemia, this is the second most common type of leukemia seen in adults, accounting for about 7,000 new cases of leukemia each year. The American Cancer Society estimated that 10,020 Americans (6,280 men and 3,740 women) would be diagnosed with it in 2006. Chronic lymphocytic leukemia often occurs during or after middle age; it rarely occurs in children. CLL usually progresses slowly.
Chronic Lymphocytic Leukemia and Blood Cells
Normally, the body produces bone marrow stem cells (immature cells) that develop into mature blood cells. The three types of mature blood cells include:
- Red blood cells that carry oxygen and other materials to all tissues of the body
- White blood cells that fight infection and disease
- Platelets that help prevent bleeding by causing blood clots to form.
In chronic lymphocytic leukemia, too many stem cells develop into a type of white blood cell called lymphocytes. The three types of lymphocytes include:
- B lymphocytes that make antibodies to help fight infection
- T lymphocytes that help B lymphocytes make antibodies to fight infection
- Natural killer cells that attack cancer cells and viruses.
With chronic lymphocytic leukemia, the lymphocytes are not able to fight infection very well, and as the amount of lymphocytes increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may result in infection, anemia, and easy bleeding.
Risk Factors for Chronic Lymphocytic Leukemia
No one knows the exact
causes of chronic lymphocytic leukemia, and doctors can seldom explain why one person will get
CLL and another person will not. However,
leukemia research has shown that people with certain risk factors are more likely than others to develop chronic lymphocytic
leukemia. A risk factor is anything that increases a person's chances of developing a condition.
Risk factors for chronic lymphocytic leukemia include:
- Being middle-aged or older, male, or Caucasian
- A family history of chronic lymphocytic leukemia or cancer of the lymph system
- Having relatives who are Russian Jews or Eastern European Jews.
Symptoms of Chronic Lymphocytic Leukemia
Like all blood cells,
leukemia cells travel through the body. Depending on the number of abnormal cells and where these cells collect, people with chronic lymphocytic leukemia may have a number of symptoms.
Diagnosing Chronic Lymphocytic Leukemia
Tests that examine the blood, bone marrow, and lymph nodes are used to detect and diagnose chronic lymphocytic leukemia.
Tests and procedures that may be used to make a diagnosis include:
- Physical exam (along with a review of the person's medical history)
- Complete blood count
- Cytogenetic analysis
- Immunophenotyping
- Bone marrow aspiration and biopsy.
Physical Exam and Medical History
A physical exam entails an exam of the body to check general signs of health, including checking for signs of chronic lymphocytic leukemia, such as lumps or anything else that seems unusual. The healthcare provider will also take and review a history of the person's health habits and past illnesses and treatments.
Complete Blood Count
A complete blood count (CBC) is a procedure in which a sample of blood is drawn and checked for the:
- Number of red blood cells, white blood cells, and platelets
- Amount of hemoglobin (the protein that carries oxygen) in the red blood cells
- Portion of the blood sample made up of red blood cells.
Cytogenetic Analysis
A cytogenetic analysis is a test in which cells in a sample of blood or bone marrow are viewed under a microscope to look for changes in the structure or number of chromosomes in the lymphocytes.
Immunophenotyping
Immunophenotyping is a test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out if malignant lymphocytes (cancer) began from the B lymphocytes or the T lymphocytes.
Bone Marrow Aspiration and Biopsy
A bone marrow aspiration and biopsy involves the removal of a small piece of bone and bone marrow by inserting a needle into the hipbone or breastbone. A pathologist will then view both the bone and bone marrow samples under a microscope to look for abnormal cells.
Stages of Chronic Lymphocytic Leukemia
After the doctor diagnoses chronic lymphocytic
leukemia, it's then necessary to determine how far the cancer has spread in the blood and bone marrow. This process is known as staging. It is important to know the stage of
CLL in order to plan the best treatment.
The stages of chronic lymphocytic leukemia include:
- Stage 0
- Stage I
- Stage II
- Stage III
- Stage IV
- Recurrent.
Treatment for Chronic Lymphocytic Leukemia
- The chronic lymphocytic leukemia stage (see CLL Treatment by Stage)
- Red blood cell, white blood cell, and platelet blood counts
- Whether the liver, spleen, or lymph nodes are larger than normal
- The response to initial treatment
- Whether the cancer has recurred (come back)
- Whether there are symptoms, such as fever, chills, or weight loss.
Specific treatment options include:
- Watchful waiting
- Radiation therapy
- Chemotherapy
- Surgery
- Monoclonal antibody therapy.
Choosing the most appropriate treatment for chronic lymphocytic leukemia is a decision that ideally involves the affected person, the family, and the healthcare team.
Prognosis With Chronic Lymphocytic Leukemia
A person's chronic lymphocytic leukemia prognosis (chance of recovery) will depend on factors such as:
- Whether there is a change in the DNA and the type of change, if there is one
- Whether lymphocytes are spread throughout the bone marrow
- The stage of chronic lymphocytic leukemia
- Whether the disease gets better with treatment or has recurred
- The person's general health
- Whether the chronic lymphocytic leukemia progresses to lymphoma or prolymphocytic leukemia.
Chronic Lymphocytic Leukemia: A Summary
Key information about chronic lymphocytic leukemia includes the following:
- Chronic lymphocytic leukemia is a type of cancer in which the bone marrow makes too many lymphocytes
- Examples of risk factors for chronic lymphocytic leukemia include having a family history of the disease and being middle-aged or older, male, or Caucasian.
- Possible signs of chronic lymphocytic leukemia include swollen lymph nodes and tiredness
- Tests that examine the blood, bone marrow, and lymph nodes are used to detect and diagnose chronic lymphocytic leukemia
- Factors that affect treatment options and prognosis for chronic lymphocytic leukemia include such things as the stage of the cancer and whether it has recurred
- The American Cancer Society estimated that 10,020 Americans would be diagnosed with chronic lymphocytic leukemia in 2006.
