Allergies and risk of head and neck cancer: a case-control study.

Although the relationship between allergies and cancer has been investigated extensively, the role of allergies in head and neck cancer (HNC) appears less consistent. It is unclear whether allergies can independently influence the risk of HNC in the presence of substantial environmental risk factors, including consumption of alcohol, betel quid, and cigarettes. This study aims to find this association. We examined the relationship between allergies and HNC risk in a hospital-based case-control study with 300 cases and 375 matched controls. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals, controlling for age, sex, tobacco smoking and opium usage history, alcohol consumption, and socioeconomic status. Our study showed a significant reduction in the risk of HNC associated with allergy symptoms after adjusting for confounders. The risk of HNC was greatly reduced among those with any type of allergy (OR 0.42, 95% CI 0.28, 0.65). The ORs were considerably reduced by 58-88% for different kinds of allergies. The risk of HNC reduction was higher in allergic women than in allergic men (71% vs. 49%). Allergies play an influential role in the risk of HNC development. Future studies investigating immune biomarkers, including cytokine profiles and genetic polymorphisms, are necessary to further delineate the relationship between allergies and HNC. Understanding the relationship between allergies and HNC may help to devise effective strategies to reduce and treat HNC.