[Recent data on the epidemiology of non Hodgkin's lymphoma.]

Non-Hodgkin's lymphoma is a common condition whose incidence has increased by 75 % over the last 15 years. The HIV epidemic is among the factors that have contributed to this increase : patients with AIDS have 1% annual risk of developing non-Hodgkin's lymphoma, and the increase in survival of AIDS patients has led to an increase in the frequency of AIDS-associated lymphomas. A number of other viruses are directly involved in the occurence of lymphomas, such as the HTLV-1 and the EBV: The HSV type 8 has recently been incriminated in the occurence of lymphomas located in the cavities of the body. The role of the hepatitis C virus in the occurence of lymphoma is controversial. Inherited or acquired immunodeficiencies (e.g., due to treatment for an autoimmune disease or transplant) are associated with an increased incidence of lymphoma. The role of toxic chemicals, especially those used in farming, is receiving increasing attention. A number of infectious diseases promote the occurence of lymphomas; the best illustration of this link is the association between Helicobacter pylori and primary low-grade gastric lymphomas.