Lymphoma risk in livestock farmers: Results of the Epilymph study Pierluigi Cocco 1 , Giannina Satta 1 , Ileana D’Andrea 1 , Tinucia Nonne 1 , Giuseppe Udas 1 , Mariagrazia Zucca 2 , Andrea ’t Mannetje 3 , Nikolaus Becker 4 , Silvia de Sanjos e 5 , Lenka Foretova 6 , Anthony Staines 7 , Marc Maynadi e 8 , Alexandra Nieters 9 , Paul Brennan 10 , Maria G. Ennas 2 and Paolo Boffetta 11 1 Department of Public Health, Clinical and Molecular Medicine, Occupational Health Section, University of Cagliari, Italy 2 Department of Biomedical Sciences, University of Cagliari, Italy 3 Centre for Public Health Research, Massey University, Wellington, New Zealand 4 German Cancer Research centre, Heidelberg, Germany 5 Catalan Institute of Oncology, and Centro de Investigaci on Biom edica en Red de Epidemiologı ´a y Salud P ublica (CIBERESP), Barcelona, Spain 6 Department of Cancer Epidemiology and Genetics, Brno, Czech Republic 7 School of Nursing and Human Sciences, Dublin City University, Dublin, Ireland 8 Dijon University Hospital, Dijon, France 9 Centre of Chronic Immunodeficiency, University of Freiburg, Germany 10 International Agency for Research on Cancer, Lyon, France 11 The Tisch Cancer Institute and Institute for Translational Epidemiology, Mount Sinai School of Medicine, New York, NY and International Prevention Research Institute, Lyon, France We explored the risk of lymphoma and its most prevalent subtypes associated with occupational contact with livestock, and whether risk was modified by age at first contact, in 2,348 incident lymphoma cases and 2,462 controls who participated in the EPILYMPH case–control study. A detailed occupational history was collected in cases and controls, including working in a livestock farm, species of livestock, its approximate number and circumstances of contact. For each disease outcome, and each type of livestock, odds ratios (OR) and their 95% confidence intervals (95% CI) were calculated using unconditional logistic regression, adjusting for age, gender, education and center. Lymphoma risk (all subtypes combined) was not increased amongst those exposed to contact with any livestock (OR 5 1.0, 95% CI 0.8–1.2). Overall, we did not observe an association between occupational contact with livestock and risk of lymphoma (all types) and B-cell lymphoma. The risk of diffuse large B cell lyphoma (DLBCL) was significantly lower amongst subjects who started occupational contact with any species of livestock before or at age 12 (OR 5 0.5, 95% CI 0.2–0.9), but not at older ages. A significant heterogeneity in risk of B cell lymphoma by age at first contact was detected for contact with cattle, poultry and swine. Early occupational contact with livestock might be associated with a decrease in risk of B cell lymphoma. Numerous infectious agents and environmental factors seem to be implicated in the etiology of the various lymphoma subtypes, by promoting or interacting with genetic or acquired immune system disruption. 1 Among these factors, contact with farm animals may play a role in modulating the risk of lymphoma, possibly through transmission to humans of biological agents, such as the bovine leukemia virus, the avian flu virus and the agents of several sheep diseases, such as Chlamydia psittaci, and the blue-tongue and foot and mouth disease vectors. 2 Recent research has suggested a potential role for exposure to endotoxin, a component of the outer membrane of Gram-negative bacteria, and a common environmental contaminant associated with poverty, crowd- ing, pets, household cleanliness and the rural environment Key words: lymphoma, B-cell, Agriculture, Livestock, Zoonoses, immune response Grant sponsor: European Commission, 5th Framework Program, Quality of Life; Grant number: QLK4-CT-2000-00422; Grant sponsor: European Commission, 6th Framework Program; Grant numbers: FP6-2003-FOOD-2-B, 023103; Grant sponsor: Spanish Ministry of Health; Grant numbers: 04-0091, RCESP 09-10; Grant sponsor: German Federal Office for Radiation Protection; Grant numbers: StSch4261, StSch4420; Grant sponsors: La Fondation de France, the Irish Health Research Board, Italian Ministry for Education, University and Research; Grant numbers: PRIN 2007 prot. 2007WEJLZB, PRIN 2009 prot. 20092ZELR2; Grant sponsors: Italian Association for Cancer Research (AIRC, Investigator Grant 2011), German Federal Ministry for Education and Research; Grant number: BMBF-01-EO-0803 DOI: 10.1002/ijc.27908 History: Received 26 Jun 2012; Accepted 17 Sep 2012; Online 15 Oct 2012 Correspondence to: Pierluigi Cocco, Department of Public Health, Clinical and Molecular Medicine, Occupational Health Section, University of Cagliari, Asse Didattico, SS 554, km 4,500, 09042 Monserrato (Cagliari), Italy, Tel.: þ39-0706754438, Fax: þ39-0706754728, E-mail: coccop@medicina.unica.it Epidemiology Int. J. Cancer: 132, 2613–2618 (2013) V C 2012 UICC International Journal of Cancer IJC