Pesticide Use Associated with Increased Risk of NHL
(Beyond Pesticides, May 17, 2006) According to an early online publication in the journal Blood, agricultural exposure to insecticides, herbicides, and fumigants are associated with increased risk of developing t(14;18)-positive non-Hodgkin’s lymphoma (NHL).
Non-Hodgkin’s lymphoma is a cancer of the immune system. There are several different types of NHL, which are differentiated by the type of immune cell that is cancerous, the characteristics of the cancerous cell, and different genetic mutations of the cancerous cells. Treatment for NHL varies depending on NHL type, patient age, and other existing medical conditions.
The incidence of NHL has been increasing over the past several decades. The reasons for this increase are unknown. As well, the causes of most lymphomas are unknown; the few with known causes include those associated with specific bacteria (Helicobacter pylori in gastric lymphoma) and viruses such as the Epstein-Barr virus (Burkitt’s lymphoma), HIV-related lymphomas, body cavity lymphomas (human herpes virus-8) or T-cell lymphoma (HTLV-1). However, none of these specific causes explain the increased incidence of lymphomas in recent years. There is speculation that exposure to chemicals, such as certain solvents, pesticides, herbicides, and water contaminated with nitrate, are responsible for the increased incidence of NHL.
Researchers from the Northwestern University, University of Nebraska Medical Center, and the National Cancer Institute recently conducted a study aimed at uncovering a possible association between different molecular types of NHL and exposure to agricultural pesticides. This study included 65 patients with t(14;18)-positive NHL (refers to a specific genetic alteration in a type of NHL), 107 patients with t(14;18)-negative NHL, and 1,200 individuals who have not been diagnosed with NHL.
- Patients exposed to animal insecticides, crop insecticides, herbicides, or fumigants had a 2.6 to 5.0 fold increase in the incidence of t(14;18)-positive NHL.
- There was no increased incidence of t(14;18)-negative NHL and exposure to these agents.
The researchers concluded that agricultural pesticides appear to increase the risk of developing t(14;18)-positive NHL.
These results further confirm suspicions that these agents are at least in part associated with the increased incidence of NHL over the past several decades. Additional study will likely further uncover these associations.