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

Background: Active smoking is an established risk factor for pancreatic cancer, but the role of passive smoking 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% confidence intervals (CI) were estimated using Cox proportional hazards models. Results: During 24 years of follow-up (1982-2006), 384 women were diagnosed with pancreatic cancer. Maternal smoking significantly increased the risk of pancreatic 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)