Abstract 5491: A history of allergies is associated with reduced risk of oral squamous cell carcinoma
Authors: Marni Stott-Miller, Chu Chen, David R. Doody, Stephen M. Schwartz
Journal: Cancer Research (2012)

Abstract History of any type of allergy is associated with a decreased risk of multiple types of cancers, including colorectal, cervical, esophageal, pancreatic, stomach, leukemia and glioma. It is proposed that having a history of allergies may prevent cancer by enhancing immune surveillance against tumor cells early in disease development and/or against carcinogenic infectious agents. While a few prior studies suggest an inverse relationship between history of allergies and oral squamous cell carcinoma (OSCC); they did not distinguish between oropharyngeal cancer and oral cavity cancers, and did not account for HPV infection. We compared 400 OSCC cases newly diagnosed between 1985-1995 with 613 general population controls from the Seattle-Puget Sound metropolitan areas with respect to self-reported history of allergy to each of the following: dust, pollen, mold, dogs, cats, bee stings, drugs and food. We estimated odds ratios (OR) and 95% confidence intervals (CI), adjusted for age, education level, sex, race, pack years of cigarette smoking, and lifetime average alcoholic drinks per week. We observed a small inverse association between history of any allergy and OSCC (OR=0.81, 95% CI, 0.61-1.08). This inverse association was present only for dust (OR=0.70; 95% CI,0.43-1.13), pollen (OR=0.72; 95% CI,0.51-1.02) and mold (OR=0.34; 95% CI,0.14-0.83). Additional adjustment for HPV-16 seropositivity did not materially affect the estimates. In exploratory analyses, we examined associations with dust, pollen or mold more closely, and observed stronger associations with oropharyngeal cancer (OR=0.56; 95% CI, 0.35-0.90) than with oral cavity cancer (OR=0.71; 95% CI, 0.49-1.05); although a polytomous regression model did not suggest heterogeneity by site (p=0.5). There was no effect modification by sex, cigarette smoking, alcohol consumption, HPV-16 seropositivity (for all sites or oropharynx alone), or herpes simplex virus 1 seropositivity. The inverse association with dust/pollen/mold was near null for 30 cases of oncogenic HPV DNA-positive oropharyngeal cancer (OR=0.86; 95% CI, 0.38-1.94) and stronger for 46 cases of oncogenic HPV DNA-negative oropharyngeal cancer (OR=0.53; 95% CI, 0.24-1.19). These results suggest that a history of allergies to dust, pollen or mold may confer some protection against OSCC. That the inverse association was particularly apparent for oropharyngeal SCC would be consistent with heightened immune surveillance, due to the substantial amount of lymphatic tissue in this organ. Whether the inverse association involves an immune response to HPV or other antigen, or other carcinogenic mechanism, remains to be determined in more definitive studies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5491. doi:1538-7445.AM2012-5491