written by: CherylJ
• edited by: Diana Cooper
• updated: 11/17/2010
Lymphoma is a cancer of the lymph system, which is part of the immune system. Lymphoma arises when the DNA of lymph cells becomes damaged, causing the cells to grow uncontrollably. The cells continue growing and eventually form a mass, or tumor.
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Lymphoma is the collective name for cancers of the lymphatic system, which is part of the body’s immune system. Lymphomas are cancers that affect the lymphocytes, or a type of white blood cell. Lymphomas are grouped into Hodgkin’s lymphoma, also called Hodgkin’s disease, and non-Hodgkin’s lymphoma, or NHL. NHL is more common than Hodgkin’s lymphoma, and it consists of at least 20 subtypes. The type of lymphoma is determined by characteristics of the affected cells. Lymphomas affect either B cells or T cells. B cells produce antibodies that attack foreign bodies, such as bacteria and viruses. T cells directly attack and kill the invading agents.
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What Causes Lymphoma
The basic cause of lymphoma is similar across all subtypes. Lymphocytes turn cancerous when the DNA of an individual cell becomes damaged. The damaged lymphocyte no longer obeys the natural factors controlling cell growth, division, and death. As a result, the damaged lymphocytes grow too large, multiply too often, and fail to follow the natural cell cycle and die. The damaged cells, now called lymphoma cells, continue dividing and replicating the damaged DNA. The lymphoma cells accumulate and produce a mass in the lymph nodes. The mass attracts additional normal lymphocytes to control the overgrowth, which only contributes to the mass and further enlarges the lymph nodes.
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Although the uncontrolled growth process is understood, the precise mechanism that initiates the cancerous growth cycle in unknown. Certain risk factors associated with lymphoma have been identified. Not everyone who develops lymphoma has a recognizable risk factor, and people with one or more risk factors never go on to develop a lymphoma.
Exposure to chemicals, including pesticides and herbicides, is linked with lymphoma. Solvents, such as benzene, acetone, turpentine, toluene, and alcohols, are found in a number of commonly used products, including gasoline. The incidence of lymphoma tends to be higher in agricultural areas, largely because of chemicals found in pesticides and herbicides.
Other than chemical exposure, older age increases a person’s risk for developing lymphoma, especially NHL. Medications that suppress the immune system, such as anti-rejection drugs, also raise a person’s risk for developing lymphoma. A history of certain infections also is associated with an increased risk. Epstein-Barr virus, human immunodeficiency virus, hepatitis C, and infection with Helicobacter pylori are all linked to lymphoma.
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Hodgkin’s Disease vs NHL
Hodgkin’s disease and NHL share similarities, but some risk factors differ. Both lymphomas are associated with a compromised immune system or past infection, most notably Epstein-Barr virus. Hodgkin’s disease is also associated with previous exposure to mononucleosis or human T-lymphotropic virus. Whereas NHL is rarely linked with an inherited condition, Hodgkin’s disease tends to occur in families. Hodgkin’s disease tends to occur in younger people than NHL, usually in people aged 15 to 40 years or older than 55 years. NHL occurs most often in people older than 60 years of age.
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LymphomaInfo.net: What Causes Lymphoma? http://www.lymphomainfo.net/lymphoma/causes.html