A prospective study of periodontal disease and pancreatic cancer.

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Background Two previous cohort studies reported positive associations between tooth loss or periodontitis and pancreatic cancer risk. However, residual confounding by smoking or other covariates may have accounted for these findings. Methods Data on history of periodontal disease was obtained at baseline and every other year thereafter in a cohort of 51,529 male health professionals aged 40 to 75 years. A total of 216 incident pancreatic cancer cases were documented during 16 years of follow-up. Multivariable relative risks (MV RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models controlling for potential confounders, including detailed smoking history. Results Men with a history of periodontal disease had a 63% increase in risk of pancreatic cancer after adjusting for age, history of smoking, diabetes, BMI, physical activity and dietary factors (relative risk [RR] = 1.63, 95% confidence interval [CI] = 1.19-2.22, compared to men without periodontal disease). A greater than 2.5-fold increase in risk of pancreatic cancer was observed for men who reported a history of periodontal disease as well as tooth loss in the past four years (RR = 2.69, 95% CI = 1.69-4.30, compared with men who reported neither condition). In contrast, baseline number of natural teeth and cumulative tooth loss during follow-up were not strongly associated with pancreatic cancer in multivariable analyses adjusting for confounding variables. Conclusion Periodontal disease may increase the risk of pancreatic cancer through plausible biological mechanisms, such as systemic inflammation or increased stomach nitrosamine levels, but confirmation of this association is necessary.