Pancreatic Cancer Risk in Relation to Lifetime Smoking Patterns, Tobacco Type, and Dose-Response Relationships.

BACKGROUND: Despite smoking being a well-established risk factor for pancreatic cancer, there is a need to further characterize pancreatic cancer risk according to lifespan smoking patterns and other smoking features, such as tobacco type. Our aim was to deeply investigate them within a large European case-control study. METHODS: Tobacco smoking habits and other relevant information were obtained from 2,009 cases and 1,532 controls recruited in the PanGenEU study using standardized tools. Multivariate logistic regression analysis was performed to evaluate pancreatic cancer risk by smoking characteristics and interactions with other pancreatic cancer risk factors. Fractional polynomials and restricted cubic splines were used to test for nonlinearity of the dose-response relationships and to analyze their shape. RESULTS: Relative to never-smokers, current smokers [OR = 1.72; 95% confidence interval (95% CI), 1.39-2.12], those inhaling into the throat (OR = 1.48; 95% CI, 1.11-1.99) or chest (OR = 1.33; 95% CI, 1.12-1.58), and those using nonfiltered cigarettes (OR = 1.69; 95% CI, 1.10-2.61), were all at an increased pancreatic cancer risk. Pancreatic cancer risk was highest in current black tobacco smokers (OR = 2.09; 95% CI, 1.31-3.41), followed by blond tobacco smokers (OR = 1.43; 95% CI, 1.01-2.04). Childhood exposure to tobacco smoke relative to parental smoking was also associated with increased pancreatic cancer risk (OR = 1.24; 95% CI, 1.03-1.49). Dose-response relationships for smoking duration, intensity, cumulative dose, and smoking cessation were nonlinear and showed different shapes by tobacco type. Effect modification by family history of pancreatic cancer and diabetes was likely. CONCLUSIONS: This study reveals differences in pancreatic cancer risk by tobacco type and other habit characteristics, as well as nonlinear risk associations. IMPACT: This characterization of smoking-related pancreatic cancer risk profiles may help in defining pancreatic cancer high-risk populations.