Association of tooth loss and periodontal disease with all-cause mortality in cancer survivors: A cohort study based on NHANES

Background: Increasing evidence supports the association between impaired oral health and elevated mortality. However, there is currently a lack of research on the impact of tooth loss and periodontal disease on survival outcomes in cancer survivors. This study aims to clarify the effect of tooth loss and periodontitis on all-cause mortality on cancer survivors. Methods: The clinical data of cancer survivors were collected from National Health and Nutrition Examination Survey (NHANES) 1999-2018. Mortality data were obtained by linking to records in the National Death Index until December 31, 2019. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal threshold for discriminating mortality based on the number of teeth lost. Kaplan-Meier survival curves and Cox regression analysis were performed to calculate hazard ratios (HRs) and 95 % confidence intervals (95 % CI) for tooth loss and periodontitis. Results: A total of 3271 cancer survivors were assessed for tooth loss status, while 1267 patients were evaluated for periodontitis status. The prevalence of any tooth loss and CDC-AAP periodontitis was 83.5 % and 47.2 %, respectively. The ROC curve showed the cut-off point of tooth loss for predicting mortality is > 5. Cancer survivors with tooth loss>5 had significantly lower bone density (1.06 vs. 1.13 g/cm2, P < 0.001), elevated C-reactive protein level (0.3 vs. 0.18 mg/ dL, P < 0.001), and a trend of lower lean body mass (46.9 vs. 47.6 kg, P = 0.093). Besides, cancer survivors with severe periodontitis also exhibited elevated C-reactive protein level (0.34 vs. 0.21 mg/dL, P = 0.033). All-cause mortality significantly increased in cancer survivors with either tooth loss>5 (HR = 1.290, P = 0.001) or severe CDC-AAP periodontitis (HR = 1.682, P = 0.016) in the multivariate Cox regression analysis. Conclusion: Tooth loss and periodontitis are strong risk factors for reduced overall survival in cancer survivors. Cancer survivors should emphasize diligent oral hygiene and consistent dental check-ups to optimize long-term oral health. The causal relationship between oral health and survival rates in cancer survivors requires further validation through randomized controlled trials.