Poultry and livestock exposure and cancer risk among farmers in the agricultural health study

Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Cancer Causes and Control (Impact Factor: 2.74). 03/2012; 23(5):663-70. DOI: 10.1007/s10552-012-9921-1
Source: PubMed


The purpose of this study is to evaluate cancer risk associated with raising animals as commodities, which is associated with a variety of exposures, such as infectious agents and endotoxins.
Information was available for 49,884 male farmers in the Agricultural Health Study, who reported livestock and poultry production at enrollment (1993-1997). Cancer incidence data were obtained through annual linkage to state registries. Using Poisson regression analyses, we evaluated whether the number and type of animals raised on the farm impacted cancer risk.
Overall, 31,848 (63.8%) male farmers reported raising any animals. Lung cancer risk decreased with increasing number of livestock on the farm (p trend = 0.04) and with raising poultry (Relative Risk (RR) = 0.6; 95% confidence interval (CI): 0.4-0.97). Raising poultry was associated with an increased risk of colon cancer (RR = 1.4; 95% CI: 0.99-2.0) with further increased with larger flocks (p trend = 0.02). Risk of non-Hodgkin lymphoma was also elevated in those who raised poultry (RR = 1.6; 95% CI: 1.0-2.4), but there was no evidence of increased risk with larger flocks (p trend = 0.5). Raising sheep was associated with a significantly increased risk of multiple myeloma (RR = 4.9; 95% CI: 2.4-12.0). Performing veterinary services increased the risk of Hodgkin lymphoma (RR = 12.2; 95% CI: 1.6-96.3).
We observed an inverse association between raising poultry and livestock and lung cancer risk and some evidence of increased risk of specific lymphohematopoietic malignancies with specific types of animals and performing veterinary services. Further research into associations between raising animals and cancer risk should focus on identification of etiologic agents.

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    • "However, some subsequently published literature provides conflicting evidence regarding the effect of endotoxin exposure on lung cancer. Reduced lung cancer risks continue to be observed in studies of UK cotton textile (McElvenny et al, 2011) and US agricultural cohorts (Beane Freeman et al, 2012), whereas moderately elevated risks associated with endotoxin *Correspondence: Professor H Checkoway; E-mail: Received 20 February 2014; revised 5 May 2014; accepted 11 May 2014; published online 12 June 2014 & 2014 Cancer Research UK. "
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