Is periodontal disease associated with increased risk of colorectal cancer? A meta-analysis

Objective: Colorectal cancer (CRC) is a commonly diagnosed cancer. Previous studies investigating the relationship between periodontal disease (PD) and CRC showed controversial conclusions. This meta-analysis is to explore the association between PD and CRC.

Methods: Observational studies that explore the association between CRC and PD were included in this meta-analysis. A comprehensive literature search in 7 electronic databases to identify all relevant studies published prior to February 2020. The Newcastle-Ottawa Quality Assessment Scale was used to evaluate the quality each study. The pooled relative risk (RR) and 95% confidence interval (CI) were used to estimate the association between the PD and CRC risk.

Results: A total of 838 articles were obtained from database searching and 4 articles were obtained from other sources, and 13 articles with 14 studies involving 634,744 participants were included. An association between PD and increased CRC incidence was found, periodontal disease patients were 21% (95%CI, [1.06, 1.38], I² =83.9%) more likely to develop colorectal cancer than people with healthy oral cavity. But there is no significant association between PD and CRC mortality. The heterogeneity of this meta-analysis was relatively high, I² was 83.9% (95%CI, [72.7%, 90.5%]), chi-squared of Q test was 62.18, but sensitivity analysis confirmed the stability of the result. Funnel plot, Egger's test and Begg's test found no publication bias of analysis.

Conclusion: The current meta-analysis demonstrates an association between PD and CRC, indicating that early CRC screening is necessary for people with poor oral health, and oral health improvement might be beneficial for reducing CRC risk.