title: Aspirin and nonsteroidal anti-inflammatory drug use and risk of pancreatic cancer: a meta-analysis.
abstract: BACKGROUND
  The association between use of nonsteroidal anti-inflammatory drugs (NSAID), including aspirin, and risk of pancreatic cancer is controversial. We did a meta-analysis to summarize available evidence from epidemiologic studies investigating the relation between use of aspirin or other NSAIDs and the risk of pancreatic cancer.
  
  
  METHODS
  We identified potential studies by searching the MEDLINE database (from 1966 to October 2006) and by reviewing the reference lists of pertinent publications. Studies were eligible for inclusion if they met the following criteria: (a) had a case-control or prospective design, (b) examined exposure to aspirin or NSAIDs, (c) the outcome was pancreatic cancer incidence or mortality, and (d) they provided a relative risk (RR) estimate with corresponding confidence interval or sufficient information to permit their calculation. Study-specific RR estimates were pooled using a random effects model.
  
  
  RESULTS
  A total of 11 studies (3 case-control studies, 7 cohort studies, and 1 randomized trial), involving 6,386 pancreatic cancer cases, was included in the meta-analysis. The summary RR estimate did not indicate any association between aspirin/NSAID use and risk of pancreatic cancer [any/regular use versus nonregular/never use: RR, 1.01; 95% confidence interval (95% CI), 0.91-1.11; P(heterogeneity) = 0.09]. Neither use of aspirin, nonaspirin NSAIDs, nor overall NSAIDs were associated with pancreatic cancer risk. There was also no overall association with frequent (six or more tablets/times per week versus none: RR, 0.86; 95% CI, 0.61-1.23) or long-term (>or=20 years) use of aspirin (RR, 1.21; 95% CI, 0.74-1.96).
  
  
  CONCLUSIONS
  Current epidemiologic evidence does not indicate that use of aspirin or NSAIDs is associated with the risk of pancreatic cancer.
authors.affiliation: Division of Nutritional Epidemiology, The National Institute of Environmental Medicine, Karolinska Institutet, P.O. Box 210, SE-17177 Stockholm, Sweden. susanna.larsson@ki.se
authors.forename: Susanna C
authors.initials: SC
authors.lastname: Larsson
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: Leif
authors.initials: L
authors.lastname: Bergkvist
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D010190:Pancreatic Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D012306:Risk; D013548:Sweden / Q000453:epidemiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin