Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL)

  • Is a type of blood cancer that begins in the bone marrow
  • Can progress either slowly or quickly depending on the form it takes

Click here to access CLL statistics.

What You Should Know

  • CLL is the most common type of leukemia in adults in Western countries.
  • Hematologists and oncologists are specialists who treat people who have CLL or other types of blood cancer.
  • Some people have CLL that grows slowly while other people have CLL that grows faster.
  • CLL patients have a number of effective treatment options available to them.
  • For low-risk CLL, watch and wait or active surveillance may be an appropriate treatment approach.
  • Many people with CLL live good-quality lives for years with medical care.

What You Should Do

  • Talk with your doctor about your diagnostic tests and what the results mean.
  • Talk with your doctor about all your treatment options and the results you can expect from treatment.
  • Ask your doctor whether a clinical trial is a good treatment option for you.

To download lists of suggested questions to ask your healthcare providers, click here.

How Does CLL Develop?

The DNA (genetic material) of a developing stem cell in the bone marrow is damaged. This is called an “acquired mutation.”

  • Stem cells form blood cells (red cells, white cells and platelets).

This damaged cell becomes a leukemic cell and multiplies into many CLL cells. The CLL cells grow and survive better than normal cells.

  • CLL doesn't completely interfere with the development of mature red cells, white cells and platelets. Therefore, CLL is generally less severe than acute leukemia.

As a result, the number of healthy blood cells (red cells, white cells and platelets) is usually lower than normal.

  • Anemia is a condition when there is a low number of red cells in the blood which can cause fatigue and shortness of breath.
  • Neutropenia is a condition when there is a low number of white cells so that the immune system can't effectively guard against infection due to a lack of neutrophils (a type of white cell).
  • Thrombocytopenia is a condition when there is a low number of platelets which can cause bleeding and easy bruising with no apparent cause.
  • Low numbers of all three blood cell counts is called pancytopenia.

CLL doesn't completely interfere with the development of mature red cells, white cells and platelets. Therefore, CLL is generally less severe than acute leukemia. Some people with CLL have no symptoms when they are first diagnosed by a routine blood test. However, if CLL progresses it can affect the number of healthy blood cells and lead to complications. 

Risk Factors

Doctors don't know why some cells become leukemic cells and others don't. For most people who have chronic lymphocytic leukemia (CLL), there are no obvious reasons why they developed the disease.

  • Some studies have associated exposure to Agent Orange, an herbicide used during the Vietnam War, with an increased risk of CLL. For more information, visit the VA website.
  • Some studies suggest that exposure to benzene in the workplace increases the risk of CLL
  • Genetic factors likely play a role in the development of CLL, as some families have more than one family member with the disease
  • CLL generally affects older people and more males than females
     

A Risk for Vietnam Veterans

Researchers have found a potential association between CLL and exposure to herbicides like Agent Orange used during the Vietnam conflict from 1961 to 1971. The U.S. Department of Veterans Affairs (VA) entitles those exposed to receive disability compensation. If you have CLL and think you may have been exposed to Agent Orange or other herbicides, you're entitled to benefits. The VA is urging Vietnam veterans to apply for compensation to begin processing their claims. For more information, visit the U.S. Department of Veterans Affairs website.

Source: Chronic Lymphocytic Leukemia. Reviewed by Mazie Tsang, MD, MAS, MS 

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