Combination of recurrent oral aphthae and dry eye syndrome may constitute an independent risk factor for oral cavity cancer in elderly women

BACKGROUND: Few studies have evaluated the risk of oral cavity cancer (OC) in patients with recurrent oral aphthae (ROA) and dry eye syndrome (DES). This study assessed the risk of OC in patients who had received diagnoses of ROA and DES in Taiwan. METHODS: A population-based frequency-matched case–control study was conducted in which data were analyzed from the National Health Insurance Research Database of Taiwan. Patients with ROA and DES were identified as the case cohort. Patients and controls without ROA and DES were frequency matched (1:4) on the basis of age, sex, monthly income, geographical location, and urbanization level. Chi-squared tests were conducted to compare demographic factor distributions between the patients and controls. Cox proportional hazards models were used to calculate the adjusted hazard ratios (aHRs) and 95% CI of OC diagnoses among the patients and controls. Risk consistency between the two cohorts was determined using subgroup analysis. RESULTS: A total of 7,110 patients with ROA and DES and 28,388 controls were identified. The OC risk was significantly higher for female patients than controls (aHR=3.41, 95% CI=1.69–6.86). Furthermore, women aged 50–69 years exhibited a higher risk of OC than those in the other age groups. Female patients aged 50–59 years exhibited the highest aHR for OC (aHR=5.56, 95% CI=1.70–18.25), followed by those aged 60–69 years (aHR=4.34, 95% CI=1.26–15.99). CONCLUSION: ROA and DES may be associated with a high risk of OC in elderly women.