Leukemia
with John Nesbitt, MD
How are different types of leukemia treated?
Nearly 45,000 American men and women will be diagnosed with leukemia in 2007. Sadly, about half will die of the disease. According to John Nesbitt, MD, Chief of the Division of Hematology at GBMC, the disease is particularly devastating because it affects the white blood cells and other circulating elements in the blood, including the red blood cells and the platelets, which are also made in the bone marrow. Lymph glands and the spleen may also be affected. “Genetic alteration of the stem cell or other early white cell precursors is thought to be the causative event in leukemia,” says Dr. Nesbitt.
Under normal conditions, the body’s white blood cells help fight off infection. When a person has leukemia, his or her bone marrow produces a large number of abnormal white blood cells that do not properly function. Eventually the abnormal white blood cells affect the production of normal white blood cells, red blood cells and platelets which can lead to anemia, infection, or bleeding.
“Leukemia has been classified by how fast the disease progresses and by what type of white blood cell is affected,” says Dr. Nesbitt. It is divided into two types: acute leukemia and chronic leukemia. Acute leukemia is characterized by white blood cells that remain very immature and accumulate rapidly. The cells may not die like normal cells and eventually overwhelm the production of healthy cells and disrupt the function of vital organs. Chronic leukemia is characterized by the accumulation of more mature white blood cells. The progression of the disease is slower, but eventually a shortage of normal cells can lead to infection, anemia and excessive bleeding.
Leukemia is also classified by the type of cell affected. The two main types in this classification are lymphocytic leukemia and myelogenous leukemia. Lymphocytic leukemia affects the lymphocytes, which are normally involved in the production of antibodies and are normally found in the bone marrow, lymph glands or spleen. Myelogenous leukemia affects the myeloid cells, which tend to be more involved with fighting bacterial infections.
Thus leukemia is further divided into four types, which include:
- Acute myelogenous leukemia (AML) - This type of leukemia may occur at any age but is more common in adults.
- Acute lymphocytic leukemia (ALL) - This is the most common form of leukemia among children.
- Chronic lymphocytic leukemia (CLL) - This type of leukemia is most frequently found in adults and the incidence goes up with age. Those affected may not experience many symptoms and may go for years without requiring treatment.
- Chronic myelogenous leukemia (CML) - This is more common among adults. The disease tends to progress from a chronic phase to a more accelerated phase and finally to a blastic phase that looks like AML.
Leukemia is frequently diagnosed through physical exam, blood test and bone marrow samples. If leukemia is found, there are several treatment options. “Treatment usually depends on the type of leukemia diagnosed,” says Dr. Nesbitt. “Some forms of leukemia may not require any treatment, while others may require more aggressive medications and therapies.”
Unlike other cancers, surgery is not an option because there is not a solid tumor that can be removed. Chemotherapy is the most common treatment to fight leukemia. Other options may include radiation therapy and bone marrow transplants. Acute lymphocytic leukemia in children is frequently curable with appropriate treatment but all types of leukemia in adults are much more difficult to cure. “In most adult leukemia even our best treatment approaches have only resulted in a remission of the disease,” says Dr. Nesbitt. “The use of targeted therapy, particularly in CML, has been a major advance.”
At GBMC, patients are able to receive complete care for leukemia. “GBMC has a comprehensive program for treating many different types of cancers, specifically cancers of the blood, and we have a strong mission to help with diagnosis and treatment of these diseases,” says Dr. Nesbitt.
