From May 17, 2006
Agricultural
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.