Cigar and pipe smoking, smokeless tobacco use and pancreatic cancer: An analysis from the International Pancreatic Cancer Case-Control Consortium (PanC4)

Background: Cigarette smoking is the best-characterized risk factor for pancreatic cancer. However, data are limited for other tobacco smoking products and smokeless tobacco. Materials and methods: We conducted a pooled analysis of cigar and pipe smoking and smokeless tobacco use and risk of pancreatic cancer using data from 11 case-control studies (6056 cases and 11 338 controls) within the International Pancreatic Cancer Case-Control Consortium (PanC4). Pooled odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated by unconditional multiple logistic regression models adjusted for study center and selected covariates. Results: Compared with never tobacco users, the OR for cigar-only smokers was 1.6 (95% CI: 1.2-2.3), i.e. comparable to that of cigarette-only smokers (OR 1.5; 95% CI 1.4-1.6). The OR was 1.1 (95% CI 0.69-1.6) for pipeonly smokers. There was some evidence of increasing risk with increasing amount of cigar smoked per day (OR 1.82 for ≥ 10 grams of tobacco), although not with duration. The OR for ever smokeless tobacco users as compared with never tobacco users was 0.98 (95% CI 0.75-1.3). Conclusion: This collaborative analysis provides evidence that cigar smoking is associated with an excess risk of pancreatic cancer, while no significant association emerged for pipe smoking and smokeless tobacco use.