Introduction
While the link between oral hygiene and systemic disease has been widely studied, large-scale studies specifically examining the association between oral hygiene or periodontal disease (PD) and colorectal cancer (CRC) remain scarce.
Aims & Methods
We aimed to investigate the association between oral hygiene indicators and the risk of CRC using a nationwide, population-based dataset from the Korean National Health Insurance Service (NHIS). The first was based on the National Health Screening (NHS) database, incorporating self-reported oral hygiene behaviors and dentist-conducted clinical dental examination findings. The second analysis utilized claims data from the NHIS database, focusing on PD as the primary exposure. We identified individuals aged ≥19 years newly diagnosed with CRC between January 2012 and December 2019, and controls without any history of cancer, matched at a 1:4 ratio using extensive propensity score (PS) matching. Multivariable conditional logistic regression was performed to adjust for potential confounders, including demographics, comorbidities, lifestyle factors, and laboratory values.
Results
In the NHS-based analysis, a total of 2,188,968 individuals were analyzed. Following PS matching, the matched dataset comprised 35,668 CRC cases and 141,850 controls. Several oral health indicators were significantly associated with increased CRC risk, including objective dental findings such as decayed teeth (adjusted odds ratio [aOR], 1.08; 95% confidence interval [CI], 1.05–1.11), missing teeth (aOR, 1.14; 95% CI, 1.11–1.17), severe gingivitis (aOR, 1.21; 95% CI, 1.15–1.26), and dental calculus (aOR, 1.10; 95% CI, 1.07–1.12), as well as poor oral hygiene-related behaviors or symptoms such as infrequent dental visits (aOR, 1.04; 95% CI, 1.02–1.07), poor perceived oral health (aOR,1.06; 95% CI, 1.02-1.10),
infrequent daily toothbrushing (aOR,1.20; 95% CI, 1.14–1.24), infrequent brushing before bedtime (aOR, 1.05; 95% CI, 1.02–1.08), non-use of interdental cleaning devices (aOR, 1.10; 95% CI, 1.07–1.13), and tooth pain (aOR, 1.03; 95% CI, 1.00–1.06). In the claims-based analysis, among 5,266,776 individuals, 133,482 CRC cases and 528,559 matched controls were included after PS matching. In the multivariable analysis, PD was independently associated with an increased risk of CRC (aOR, 1.03; 95% CI, 1.01–1.04). Additionally, in subgroup analyses stratified by age, sex, alcohol consumption, smoking status, and obesity, objective dental examination findings consistently showed a significant association with increased CRC risk across all subgroups.
Conclusion
Poor oral hygiene and PD were significantly associated with an elevated risk of CRC in this large-scale, population-based study. These findings highlight the potential importance of oral health in screening and prevention of CRC.
