Pesticide Use And Risk Of Hodgkin Lymphoma: Results From The North American Pooled Project (NAPP)

Lidija LATIFOVIC, Cancer Care Ontario, Canada
BEANE FREEMAN L. 2 , SPINELLI J. 3 , PAHWA M. 1,4 , BLAIR A. 2 , PAHWA P. 6 , MCLAUGHLIN J. 4,7,8,9 , DOSMAN J. 6 , HOAR ZAHM S. 2 , CANTOR K. 2 , WEISENBURGER D. 5 , DEMERS P. 4,9 , HARRIS S. 1,4,9

1 Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON, Canada
2 U.S. National Cancer Institute, Bethesda, MD, USA
3 British Columbia Cancer Agency Research Centre, University of British Columbia, Vancouver, BC, Canada
4 Occupational Cancer Research Centre, Cancer Care Ontario, Toronto, ON, Canada
5 Department of Pathology, City of Hope Medical Center, Duarte, CA, USA
6 University of Saskatchewan, Saskatoon, SK, Canada
7 Lunenfeld-Tanenbaum Research Institute, Toronto, ON, Canada
8 Public Health Ontario, Toronto, ON, Canada
9 Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada

Purpose:  The prevalence of haematological cancers is elevated in agricultural populations. It has been hypothesized that exposure to pesticides contributes to this risk. The purpose of this study was to investigate pesticide exposures and risk of Hodgkin lymphoma (HL) using pooled data from the North American Pooled Project (NAPP).   

Methods: This analysis included 507 HL cases and 1563 controls from three population-based studies conducted in Midwestern USA (1981-86) and six provinces across Canada (1991-94). Odds ratios and 95% confidence intervals were estimated for self-reported pesticide use (never/ever) and duration of use (years) using logistic regression adjusted for age, sex, place of residence and respondent status.  

Results: An increased risk of HL was observed for use of five or more insecticides (OR: 1.88, 95%CI: 1.08-3.27) relative to unexposed. Use of two or more carbamate insecticides (OR=2.45, 95%CI=1.03-5.84) was associated with more than double the risk of HL. An analysis of individual pesticides showed significant increasing trends of HL with duration of use of terbufos (>4.5 years, OR=3.34, 95%CI=1.27-8.78, p-trend=0.04) and lindane (>4.5 years, OR=2.08, 95%CI=0.95-4.56, p-trend=0.01). Ever use of carbaryl (OR=2.15, 95%CI=1.13-4.07) was associated with an increased risk relative to unexposed and a borderline significant increasing trend for HL was observed for duration of carbaryl use (p-trend=0.06).  Several other insecticides were considered in the individual analysis but an exposure-response relationship with duration of use was not found. There does not appear to be an increased risk of HL with use of fungicides and herbicides evaluated. 

Conclusions: Insecticide use, specifically use of terbufos, lindane, and carbaryl may increase the risk of Hodgkin lymphoma. 

Funding:  Canadian Cancer Society Research Institute Grant # 703055 and the U.S. National Institutes of Health Intramural Research Program of the National Cancer Institute.