Non-Hodgkins lymphoma (NHL) is a heterogenous disease. Each year, there are approximately 66,000 new cases and almost 20,000 deaths from NHL in the United States. Unlike Hodgkins disease, NHL is comprised of approximately 10 different subtypes (in the Working Formulation) and 20 different disease entities in the Revised European-American Lymphoma Classification (REAL) system.
These subtypes are grouped into 3 biologic states- low grade, intermediate grade, and high grade lymphoma. Therapy is determined by several factors, including the biologic state of the lymphoma, the stage of lymphoma, the presence or absence of symptoms (e.g., weight loss, night sweats, organ dysfunction), and the overall general health of the patient.
A number of factors, including congenital and acquired immunodeficiency states, and infectious, physical, and chemical agents, have been associated with an increased risk for NHL. Infectious agents, such as viral infections (e.g., Epstein barr virus, HIV, human T-cell leukemia virus), and bacterial infections (e.g., heliobacter pylori) may be associated with the development of NHL. Additionally, physical and chemical agents such as pesticides, solvents, arsenate, and lead, as well as hair dyes, radiation exposure (high dose), and paint thinners may also increase the risk.
Non-Hodgkins lymphoma occurs more often in patients between the ages of 40 and 70. Risk for disease recurrence and overall survival rate can be predicted by using an international prognostic index (IPI) which takes into account age, stage of disease, general health (also known as performance status), number of extra nodal sites, and presence or absence of an elevated serum enzyme named LDH (lactate dehydrogenase).