Processed meat and risk of selected digestive tract and laryngeal cancers

Background/objectives To assess the association between processed meat and the risk of selected digestive tract and laryngeal cancers. Subjects/methods We conducted a series of case-control studies between 1985 and 2007 in Italy. The studies included a total of 1475 cases of cancer of the oral cavity and pharynx, 1077 of the larynx, 716 of the esophagus, 999 of the stomach, 684 of the liver, 159 of the biliary tract, 688 of the pancreas, and a total of 9720 controls. Odds ratios (ORs), and the corresponding 95% confidence intervals (CIs), were estimated by unconditional logistic regression models, including terms for socio-demographic factors, tobacco smoking, and alcohol intake. Results Compared to the lowest tertile of processed meat consumption, the ORs for subjects in the highest one were 1.18 (95% CI 0.98-1.43) for oral cavity and pharyngeal, 1.51 (95% CI 1.18-1.91) for esophageal, 1.19 (95% CI 0.96-1.47) for laryngeal, 0.98 (95% CI 0.81-1.18) for stomach, 0.85 (95% CI 0.51-1.40) for biliary tract, 1.20 (95% CI 0.94-1.54) for liver, and 1.46 (95% CI 1.15-1.85) for pancreatic cancers. Conclusions Our findings support the hypothesis that high processed meat consumption increases esophageal and pancreatic cancers risk. Residual confounding by socio-demographic factors, tobacco smoking, and alcohol intake may, partly or largely, account for these associations. We found no overall association with other digestive tract and laryngeal cancers.