Opium use, cigarette smoking, and alcohol consumption in relation to pancreatic cancer.

Although several studies have suggested opium as a risk factor for cancers of the esophagus, stomach, larynx, lung, and bladder, no previous study has examined the association of opium with pancreatic cancer. We aimed to study the association between opium use and risk of pancreatic cancer in Iran, using a case-control design. We also studied the association of cigarette smoking and alcohol consumption with pancreatic cancer, for which little information was available from this population.Cases and controls were selected from patients who were referred to 4 endoscopic ultrasound centers in Tehran, Iran. We recruited 316 histopathologically (all adenocarcinoma) and 41 clinically diagnosed incident cases of pancreatic cancer, as well as 328 controls from those with a normal pancreas in enodosonography from January 2011 to January 2015. We used logistic regression models to calculate odds ratios (ORs) and 95% confidence intervals (CIs).After adjustment for potential confounders, opium use (OR 1.91; 95% CI 1.06-3.43) and alcohol consumption (OR 4.16; 95% CI 1.86-9.31) were significantly associated with an increased risk of pancreatic cancer. We did not find an association between ever tobacco smoking and pancreatic cancer risk (OR 0.93; 95% CI 0.62-1.39).In our study, opium use and alcohol consumption were associated with an increased risk of pancreatic cancer, whereas cigarette smoking was not.