Case-control study of risk of head and neck cancer after allergic rhinitis

Chronic inflammation has been implicated in cancer development, but the association between allergic rhinitis (AR) and head and neck cancer (HNC) remains unclear. A case-control study in Taiwan investigated this association. In the Taiwan Longitudinal Health Insurance Database 2010 the authors identified 14,913 HNC patients and 59,652 propensity-score matched controls. In the entire cohort 20.19% had a prior diagnosis of AR. The prevalence of a history of AR was significantly higher in HNC patients than in controls (26.2% versus 18.70%). In analysis adjusted for demographic factors and comorbidities, the adjusted odds ratio for previous AR in HNC patients was 1.559 (95% CI 1.494-1.627). Site-specific analysis revealed increased odds for previous AR among patients with cancer of the larynx (OR 1.537; 95% CI 1.307-1.807), hypopharynx (1.220; 1.035-1.437), nasopharynx (2.933; 2.722-3.160), sinonasal (3.100; 2.424-3.964), salivary glands (1.470; 1.158-1.865), and thyroid (1.566; 1.447-1.693). The authors conclude that these findings support a link between AR and evelated risk of developing HNC.