Tobacco smoking, alcohol consumption and pancreatic cancer risk: a case-control study in Italy

In Italy, pancreatic cancer accounts for approximately 5% of cancer-related deaths. Tobacco smoking is the major established risk factor for this cancer, whereas the role of alcohol consumption is open to debate. Between 1991 and 2008, we conducted a hospital-based case-control study on pancreatic cancer in northern Italy. Cases were 326 patients (median age 63 years) with incident pancreatic cancer admitted to major general hospitals. Controls were 652 patients (median age 63 years) with acute non-neoplastic conditions admitted to the same hospital network of cases. Multiple logistic regression was used to estimate the odds ratios (OR) and the corresponding 95% confidence intervals (CI). Pancreatic cancer was associated to current smoking (OR=1.68; 95% CI: 1.13-2.48), and the risk rose with increasing number of cigarettes/day (OR=2.04; 95% CI: 1.14-3.66 for > or = 20 cigarettes/day). No association emerged for former smokers (OR=0.98; 95% CI: 0.66-1.45). Alcohol consumption was associated to increased pancreatic cancer risk, but ORs were significant only among heavy drinkers (ORs: 2.03 and 3.42 for 21-34 and > or = 35 drinks/week, respectively). Pancreatic cancer risk was 4.3-fold higher in heavy smokers (> or = 20 cigarettes/day) and heavy drinkers (> or = 21 drinks/week) in comparison with never smokers who drunk < 7 drinks/week, which is compatible with an additive effect of these exposures. In conclusion, we found that tobacco smoking and alcohol drinking are two independent risk factors for pancreatic cancer which may be responsible for approximately one third of these cancers in our population.