title: A history of allergies is associated with reduced risk of oral squamous cell carcinoma.
abstract: OBJECTIVE
  A history of allergies is associated with a decreased risk of several types of cancers. Potential mechanisms include enhanced immune surveillance against tumor cells early in disease development and/or carcinogenic infectious agents. We tested whether allergies are inversely associated with oral squamous cell carcinoma (OSCC), accounting for factors that may modify the association, such as tumor site, stage, and HPV infection.
  
  
  METHODS
  We estimated odds ratios (OR) and 95 % confidence intervals (CI) for the association between allergy history (including different types of allergies) and OSCC, adjusted for potential confounders, among 400 cases and 613 controls. Analyses were also stratified by site, stage, and measures of HPV infection.
  
  
  RESULTS
  We observed a weak inverse association between history of any allergy and OSCC (OR = 0.81, 95 % CI 0.61-1.08). This association was present only for allergies to airborne allergens (dust/pollen/mold) (OR = 0.67; 95 % CI 0.48-0.93). The inverse associations with airborne allergies were slightly stronger for oropharyngeal SCC (OR = 0.56; 95 % CI 0.35-0.90) than for oral cavity SCC (OR = 0.71; 95 % CI 0.49-1.05) and present only for later-stage cancers (OR = 0.42; 95 % CI 0.26-0.66) as opposed to earlier-stage cancers (OR = 0.98; 95 % CI 0.66-1.46). Inverse associations were not particularly present or stronger among HPV-16-seropositive individuals or for HPV DNA-positive OSCC.
  
  
  CONCLUSIONS
  There is an inverse association between history of allergies to dust, pollen, or mold and OSCC. Whether the inverse association involves heightened immune surveillance, increased immune response to HPV or other antigen, or other carcinogenic mechanism remains to be determined in more definitive studies.
authors.affiliation: Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N., Seattle, WA 98109-1024, USA.
authors.forename: Marni
authors.initials: M
authors.lastname: Stott-Miller
authors.forename: Chu
authors.initials: C
authors.lastname: Chen
authors.forename: David R
authors.initials: DR
authors.lastname: Doody
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Carter
authors.forename: Denise A
authors.initials: DA
authors.lastname: Galloway
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Madeleine
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Schwartz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D040242:Risk Reduction Behavior; D014861:Washington / Q000453:epidemiology; D055815:Young Adult