Poor Oral Health and Risk of Respiratory Tract Cancer: A Prospective Cohort Study from the UK Biobank.

Background/objectives: The individual and combined effects of diverse dental problems on site-specific respiratory tract cancer remain insufficiently addressed. This study investigated the associations between six oral conditions-dentures, loose teeth, painful gums, bleeding gums, toothache, and mouth ulcers-and the risk of developing cancers of the lung, bronchus, larynx, and trachea, both individually and collectively.

Methods: This prospective cohort study, utilizing baseline data from the UK Biobank, analyzed 438,762 participants aged 40-69 years. Multivariable Cox proportional hazards models were employed to estimate hazard ratios (HRs) and 95% CIs for incident respiratory tract cancer associated with individual oral conditions and their cumulative impact. Effect modification by sociodemographics, lifestyle, and underlying medical conditions was further assessed.

Results: During the follow-up (median = 11.0 years), 3568 participants developed respiratory tract cancer. After adjusting for confounders, including smoking history, individuals with any oral issues exhibited a 35-76% higher risk of respiratory tract cancer (HR [95% CI]: 1.35 [1.25-1.46] for the total risk, 1.34 [1.24-1.45] for bronchus/lung cancer, and 1.76 [1.23-2.52] for laryngeal cancer). Dentures (1.48 [1.36-1.60]), loose teeth (1.36 [1.20-1.54]), and painful gums (1.25 [1.04-1.50]) had a strong association with respiratory tract cancer. The overall risk escalated progressively with the number of concurrent problems (HR [95% CI] of 1.32 [1.22-1.43] for one, 1.42 [1.25-1.62] for two, 1.57 [1.23-1.98] for three, and 1.71 [1.16-2.50] for ≥four). Associations were pronounced among smokers (p-interaction = 0.002).

Conclusions: Poor oral health is linked to a heightened risk of respiratory tract cancer, especially when coupled with smoking, underscoring the importance of oral health promotion in cancer prevention strategies.