The emerging role of oral diseases and inflammation in oral cavity cancer: a Utah population-based study

Background: Oral cavity cancer (OCC) incidence is rising disproportionately among young adults lacking traditional risk factors of tobacco and alcohol exposure. While chronic inflammation and poor oral health are suspected contributors, their role remains inadequately characterized, particularly in historically low-risk populations. Objective: To evaluate associations between OCC risk and antecedent oral, allergic, and inflammatory conditions in a population-based cohort, with stratification by age (<50 versus ≥50 years) and tobacco/alcohol use status, to identify potentially modifiable risk factors for targeted prevention strategies. Methods: This population-based case-control study analyzed 754 adults diagnosed with OCC between 1996 and 2016 and 3758 frequency-matched cancer-free controls from a statewide population database. Pre-existing oral, allergic, and inflammatory conditions were identified via International Classification of Diseases (ICD)-9/10 and Current Procedural Terminology (CPT) codes recorded ≥1 year before diagnosis. Multivariable logistic regression estimated odds ratios (ORs) adjusted for age, sex, race/ethnicity, body mass index, Charlson Comorbidity Index, and smoking status. Subgroup analyses examined effect modification by age and substance use history. Results: Pre-existing oral diseases were associated with significantly elevated OCC risk (adjusted OR = 3.2). This association was most pronounced in non-smoking/non-drinking adults <50 years (OR = 8.8). Inflammatory disorders exhibited a weaker but significant association overall (OR = 1.7), with similar magnitude in older adults (OR = 1.7), non-smoking/non-drinking individuals (OR = 1.8), and non-smoking/non-drinking adults ≥50 years (OR = 1.9). No association between allergies and OCC was observed in any subgroup. Conclusion: Oral diseases are a dominant, modifiable risk factor for OCC, especially in young adults who neither smoke nor drink, supporting routine oral health screening for all adults regardless of lifestyle factors. The consistent, albeit smaller, excess risk associated with inflammatory disorders suggests that patients with such conditions should also be considered for heightened OCC surveillance.