Passive Smoking and Pancreatic Cancer in Women: a Prospective Cohort Study

Background: Active smoking is an established risk fac-tor for pancreatic cancer, but the role of passive smok-ing in pancreatic carcinogenesis remains unclear. We aimed to examine whether environmental tobacco smoke is associated with pancreatic cancer risk. Methods: We prospectively examined 86,673 women in the Nurses ' Health Study. History of exposure to environmental tobacco smoke was assessed through questionnaires in 1982. Relative risks (RR) and 95 % con-fidence intervals (CI) were estimated using Cox propor-tional hazards models. Results: During 24 years of follow-up (1982-2006), 384 women were diagnosed with pancreatic cancer. Mater-nal smoking significantly increased the risk of pancre-atic cancer (RR, 1.42; 95 % CI, 1.07-1.89), whereas paternal smoking was not related to the risk (RR, 0.97; 95 % CI, 0.77-1.21). The risk associated with maternal smoking remained elevated, albeit not significant, among never smokers (RR, 1.52; 95 % CI, 0.97-2.39). No association was found for adult passive exposure at work or at home. Conclusions: The positive association with maternal smoking suggests that environmental tobacco smoke, potentially in utero or in early life, may be associated with pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(8):2292–6