Periodontal disease, tooth loss and colorectal cancer risk: Results from the Nurses' Health Study

Periodontal diseases including tooth loss might increase systemic inflammation, lead to immune dysregulation and alter gut microbiota, thereby possibly influencing colorectal carcinogenesis. Few epidemiological studies have examined the association between periodontal diseases and colorectal cancer (CRC) risk. We collected information on the periodontal disease (defined as history of periodontal bone loss) and number of natural teeth in the Nurses' Health Study. A total of 77,443 women were followed since 1992. We used Cox proportional hazard models to calculate multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) after adjustment for smoking and other known risk factors for CRC. We documented 1,165 incident CRC through 2010. Compared to women with 25–32 teeth, the multivariable HR (95% CI) for CRC for women with