A prospective cohort study on poor oral hygiene and pancreatic cancer risk

Poor oral hygiene has been proposed to increase the risk for pancreatic cancer. We aim to assess this hypothesis, using number of teeth, dental plaque and oral mucosal lesions examined at baseline as a proxy for oral hygiene. During 1973-74 a population-based prevalence study of oral mucosal lesions was carried out in Uppsala County in central Sweden. We followed the study population through linkages with the Swedish Cancer and Total Population registers. A total of 19,924 participants were included, and 126 pancreatic cancer cases were identified during an average of 28.7 years of follow-up. Hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) for pancreatic cancer were estimated using Cox proportional hazards regression models. Overall, subjects with fewer teeth at baseline tended to have an increased risk for pancreatic cancer, although the estimates were not statistically significant. Among subjects with more than 10 teeth, those with unacceptable dental plaque had an HR of 2.1 (95% CI: 1.0, 4.7), compared with those without dental plaque after adjustment for potential confounding factors. Individuals with Candida-related or denture-related oral mucosal lesions, or tongue lesions, compared with those without any of the three studied lesions, had a 70, 30 and 80% excess risk of developing pancreatic cancer, respectively. Presence of more than one type of studied lesions further increased the risk for pancreatic cancer. In conclusion, our findings provide evidence to support the hypothesis that poor oral hygiene plays an important role in the development of pancreatic cancer.