Periodontitis and cancer mortality: Register-based cohort study of 68,273 adults in 10-year follow-up.

Periodontitis, a multifactorial infection-induced low-grade chronic inflammation, can influence the process of carcinogenesis. We studied with 10 years follow-up of 68,273 adults-based cohort the involvement of periodontitis as a risk factor for cancer mortality. Periodontal status was defined based on procedure codes of periodontal treatment. Rate ratios and absolute differences of overall and cancer mortality rates were assessed with respect to periodontal status using multiplicative and additive Poisson regression models, respectively. We adjusted for effect of age, sex, calendar time, socio-economic status, oral health, dental treatments and diabetes. Data about smoking or alcohol consumption were not available. Altogether 797 cancer deaths occurred during 664,020 person-years accumulated over a mean 10.1-year follow-up. Crude cancer mortality rate per 10,000 person-years for participants without and with periodontitis was 11.36 (95% CI 10.47-12.31) and 14.45 (95% CI 12.51-16.61), respectively. Crude rate ratios for periodontitis indicated an increased risk of overall (RR 1.27, 95% CI 1.08-1.39) and pancreatic cancer (RR 1.69, 95% CI 1.04-2.76) mortality. After adjustment, the results showed even stronger associations of periodontitis with increased overall (RR 1.33, 95% CI 1.10-1.58) and pancreatic cancer (RR 2.32, 95% CI 1.31-3.98) mortality. A higher pancreatic cancer mortality among individuals with periodontitis contributed considerably to the difference in overall cancer mortality, but this difference was not due to pancreatic cancer deaths alone.