Cancer Strikes Out!/Definitions/ Glossary/ Common Types

Leukemia & Lymphoma

Most cancers are named for where they start. For example, lung cancer starts in the lung, and breast cancer starts in the breast. Leukemia and lymphoma are named for parts of your blood and lymphatic systems.

Leukemia
Leukemia is a cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work.

Leukemia can develop quickly or slowly. Chronic leukemia grows slowly. In acute leukemia, the cells are very abnormal and their number increases rapidly. Adult acute leukemia can often be cured. Treatments may include chemotherapy, radiation, and stem cell transplantation. Even if symptoms disappear, you might need therapy to prevent a relapse.

Lymphoma
Lymphoma is a cancer of the white blood cells, especially in the lymph nodes and spleen. There are many types of lymphoma. One type is called Hodgkin's disease, which is marked by the presence of a special type of cell called the Reed-Sternberg cell. The rest are called non-Hodgkin's lymphoma. Non-Hodgkin's lymphomas begin when a type of white blood cell, called a T cell or B cell, becomes abnormal. The cell divides again and again, making more and more abnormal cells. These abnormal cells can spread to almost any other part of the body.

Non-Hodgkin lymphomas can have an indolent (slow-growing) course or an aggressive (fast-growing) course. These subtypes behave and respond to treatment differently. Both Hodgkin and non-Hodgkin lymphomas can occur in children and adults, and treatment and outcome depend on the stage and the type of cancer.

Leukemia-Lymphoma Glossary

B-cell: A white blood cell that comes from bone marrow. As part of the immune system, B cells make antibodies and help fight infections. Also called B lymphocyte.

T-cell: One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells. T cells also produce a number of substances that regulate the immune response. Also called T lymphocyte.

Hodgkin's lymphoma: A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. In 2007, more than 8,000 new cases of Hodgkin's lymphoma were diagnosed and 1,350 adults died from the cancer.

Non-Hodgkin's lymphoma: Any of a large group of cancers of the immune system. There are many different types of non-Hodgkin's lymphoma, which can be divided into aggressive (fast-growing) and indolent (slow-growing) types and can be classified as either B-cell or T-cell non-Hodgkin's lymphoma. More than 66,000 adults were diagnosed with non-Hodgkin's lymphoma in 2007. During the same time, 19,160 adults died from the disease.

Leukemia: Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream. In 2007, there were 44,270 new adult cases of leukemia and more than 21,500 leukemia patients died.

The 4 Common Types of Leukemia:

• Chronic lymphocytic leukemia (or chronic lymphoblastic leukemia, CLL) accounts for about 7,000 new cases of leukemia each year. Most often, people diagnosed with the disease are over age 55. It almost never affects children.
  
• Acute lymphocytic leukemia (or acute lymphoblastic leukemia, ALL) accounts for about 3,800 new cases of leukemia each year. It is the most common type of leukemia in young children. It also affects adults.
  
• Chronic myeloid leukemia (or chronic myelogenous leukemia, CML) accounts for about 4,400 new cases of leukemia each year. It affects mainly adults.
  
• Acute myeloid leukemia (or acute myelogenous leukemia, AML) accounts for about 10,600 new cases of leukemia each year. It occurs in both adults and children.
  

—Source: NIH

(For latest developments in treatment, see page 11.)