John J. Spinelli, Carmen H. Ng, Jean-Philippe Weber, Joseph M. Connors, Randy D. Gascoyne, Agnes S. Lai, Angela R. Brooks-Wilson, Nhu D. Le, Brian R. Berry, Richard P. Gallagher, BC Cancer Agency, Vancouver, British Columbia, Canada, Centre de Toxicologie du Québec, Sainte-Foy, Québec
*Correspondence to John J. Spinelli, BC Cancer Agency, 675 W. 10th Avenue, Vancouver, British Columbia, V5Z 1L3 Canada
Canadian Cancer Society through the National Cancer Institute of Canada
Canadian Institutes of Health Research
Michael Smith Foundation for Health Research
Organochlorine chemicals and polychlorinated biphenyls (PCBs) have been suspected as possible risk factors for non-Hodgkin lymphoma (NHL). We investigated PCBs and organochlorine pesticides and risk of NHL in a population-based case-control study in British Columbia, Canada. Congeners of PCBs (including dioxin like congeners) and pesticides or pesticide metabolites were measured in plasma of 422 pretreatment cases and 460 control subjects. This is so far the largest study to examine organochlorines in plasma to date. Several dioxin-like PCB congeners were associated with increased risk of NHL, including dioxin-like PCB nos. 118 and 156 with odds ratios (OR) for the highest versus lowest quartile between 1.6 and 1.8. Several non-dioxin-like congeners also showed significant associations. The PCB congener with the strongest association was no. 180 with an OR for the highest versus the lowest quartile of 1.83 (95% confidence interval = 1.18-2.84). Six pesticide analytes also showed a significant association with NHL; Œ≤-hexachlorocyclohexane, p,p DDE, hexachlorobenzene, mirex, oxychlordane and trans-nonachlor. The strongest association was found for oxychlordane, a metabolite of the pesticide chlordane (highest vs. lowest quartile OR = 2.68, 95% confidence interval = 1.69-4.24). Our results provide further evidence that organochlorines contribute to NHL risk. © 2007 Wiley-Liss, Inc.