Is periodontitis a risk indicator for gastrointestinal cancers? A meta-analysis of cohort studies.

OBJECTIVE: To evaluate the association between periodontitis and the incidence and mortality of gastrointestinal cancer. METHOD: A comprehensive literature search was conducted to identify all relevant studies published prior to April 2019 according to the established inclusion criteria. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with a random-effects model. RESULTS: We identified 10 studies with 26 estimates of the relationship between periodontitis and gastrointestinal cancer. The HR for the incidence of gastrointestinal cancer in periodontitis was 1.23 (95% CI: 1.10-1.37). Subgroup analyses showed that periodontitis was associated with an increased risk of gastrointestinal cancers in prospective cohort studies and high-quality studies, North American individuals, and individuals 18 years or older, as well as when the dental status was self-reported and when the study was adjusted for smoking. A meta-analysis of nine reports demonstrated that periodontitis was associated with increased mortality from gastrointestinal cancer (HR = 1.59, 95% CI: 1.16-2.16). Additionally, periodontitis was associated with mortality from pancreatic cancer (HR = 2.20, 95% CI: 1.44-3.37); thus, periodontitis may be a risk factor for pancreatic cancer. CONCLUSION: Our meta-analysis demonstrated that periodontitis may be a risk factor for gastrointestinal cancers. Additional prospective cohort studies are warranted to confirm these findings.