What is Leukemia?

Leukemia is a disease that affects the body's white blood cells. When a person is diagnosed with leukemia, it means that his or her bone marrow is producing abnormal white blood cells.

These abnormal cells, called leukemia cells, don't function the way they are supposed to, and they don't die when they are supposed to. As a consequence, they build up in a patient's bloodstream and leave increasingly little room for healthy blood cells to do the work they need to do in order to keep the patient alive and healthy.

According to the National Cancer Institute, about 47,000 new cases of leukemia are diagnosed in the United States each year, and approximately 23,500 people die from the disease annually.

Types of Leukemia

There are four primary types of leukemia. Each one is named according to two factors: the speed at which the disease develops and the type of white blood cell that is cancerous.

• When referring to the speed of the development of the disease, the term chronic is used for slowly-developing leukemias, and acute is used for rapidly-developing leukemias.
• When referring to the blood cell, a leukemia is either lymphocytic (affecting lymphoid cells; similar terms include lymphoid and lymphoblastic) or myeloid (affecting myeloid cells; similar terms include myelogenous and myeloblastic).

The four major types of leukemia:

1. Chronic lymphocytic leukemia (CLL). This disease mainly affects adults and accounts for about 15,000 new cases each year.
2. Chronic myeloid leukemia (CML). This disease also mainly affects adults and accounts for just under 6,000 new cases each year.
3. Acute lymphocytic leukemia (ALL). This disease, which accounts for about 5,000 new cases annually, can affect adults but it more commonly affects children and is the most common subtype of leukemia among children.
4. Acute myeloid leukemia (AML). About 13,000 cases of this disease are diagnosed annually, and is diagnosed in both children and adults.

If you do the basic math, you find that these four leukemia subtypes fall below the 47,000 annual number of diagnoses. The remainder are considered extremely rare leukemia subtypes, such as hairy cell leukemia.

Advances in Leukemia Research

Recent advances in leukemia research include:

• In 2011, a paper was published detailing how a CLL patient was treated through the modification of his T-cells to express a specific protein, which caused his immune system to attack the leukemia cells.
• In 2012, researchers identified several genetic alterations that may predict a leukemia patient's prognosis and the likelihood that they will respond to specific treatments.
• Also in 2012, researchers reported on the results of whole-genome sequencing from patients whose myelodysplastic syndrome had progressed to AML, offering clues to the genetic evolution of the disease.

Source: The National Cancer Institute