title: Association between allergies and risk of pancreatic cancer.
abstract: BACKGROUND
  Less than 10% of pancreatic cancer cases survive 5 years, yet its etiology is not well understood. Studies suggest allergies are associated with reduced pancreatic cancer risk. Our study collected additional information on allergies (including skin prick test results and differentiation of allergic/nonallergic asthma), and is the first to assess possible confounding by allergy medications.
  
  
  METHODS
  A population-based case-control study was designed to comprehensively assess the association between allergy and pancreatic cancer risk. Pancreas cancer cases were diagnosed during 2011 to 2012, and identified through the Ontario Cancer Registry (345 cases). Population-based controls were identified using random digit dialing and age/sex frequency matched to cases (1,285 controls). Questionnaires collected lifetime allergy history (type of allergy, age at onset, skin prick testing results), allergy medications, and established pancreas cancer risk factors. Logistic regression was used to estimate odd ratios and test potential confounders, including allergy medications.
  
  
  RESULTS
  Hay fever was associated with a significant reduction in pancreatic cancer risk [AOR = 0.68; 95% confidence intervals (CI), 0.52-0.89], and reduction was greatest for those whose skin prick test was positive for hay fever allergens. No particular patterns were observed as regards age at onset and duration of allergy. Positive dust/mold allergy skin prick test and animal allergies were associated with a statistically significant reduced pancreatic cancer risk; AOR = 0.49; 95% CI, 0.31-0.78 and AOR = 0.68; 95% CI, 0.46-0.99, respectively. Asthma was not associated with pancreatic cancer risk.
  These findings support the growing body of evidence that suggests certain allergies are associated with reduced pancreatic cancer risk.
authors.affiliation: Authors' Affiliations: Prevention and Cancer Control, Cancer Care Ontario; Dalla Lana School of Public Health, University of Toronto; Departments of Medical Biophysics and Molecular Genetics, University of Toronto; Ontario Institute for Cancer Research; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital; and Division of General Surgery, Toronto General Hospital, Toronto, Ontario; and Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Cotterchio
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lowcock
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hudson
authors.forename: Celia
authors.initials: C
authors.lastname: Greenwood
authors.forename: Steven
authors.initials: S
authors.lastname: Gallinger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D010190:Pancreatic Neoplasms / Q000453:epidemiology* / Q000276:immunology; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens