title: Nonsteroidal anti-inflammatory drugs and risk of ovarian cancer: systematic review and meta-analysis of observational studies.
abstract: OBJECTIVE
  Several observational studies have investigated the association between nonsteroidal anti-inflammatory drug (NSAID) use and ovarian cancer risk, but with conflicting results. We performed a systematic review and meta-analysis of the association between NSAID use and ovarian cancer risk.
  
  
  METHODS
  Systematic review and meta-analysis of observational studies published until September 2012.
  
  
  METHODS
  Studies were identified from the PubMed database.
  
  
  METHODS
  Fourteen case-control and seven cohort studies were included.
  
  
  METHODS
  Pooled relative risks (RRs) with corresponding 95% confidence intervals (CI) for aspirin and non-aspirin NSAIDs, separately, were calculated. Both fixed and random effect models were applied, but only random effect pooled RRs are presented. Risk estimates for invasive and borderline ovarian tumors combined and for invasive ovarian tumors only were calculated. Furthermore, heterogeneity and publication bias were evaluated.
  
  
  METHODS
  Ovarian cancer.
  
  
  RESULTS
  In the combined analysis, a slight inverse association between use of aspirin (RR 0.93; 95% CI 0.84-1.02) and non-aspirin NSAIDs (RR 0.94; 95% CI 0.84-1.06) and ovarian cancer risk was found, although it was not statistically significant. However, the risk of invasive ovarian cancer was significantly reduced with use of aspirin (RR 0.88; 95% CI 0.79-0.98). A similar tendency was observed for non-aspirin NSAIDs, but the results were not significant.
  
  
  CONCLUSIONS
  This meta-analysis showed a slight inverse association between NSAIDs and risk of ovarian cancer. However, data suggest that a chemopreventive effect of NSAIDs may be restricted to invasive ovarian tumors. Further research on NSAIDs and ovarian cancer is needed before definite conclusions can be drawn.
authors.affiliation: Virus, Lifestyle and Genes, Danish Cancer Society Research Center, Strandboulevarden 49, Copenhagen, Denmark.
authors.forename: Louise
authors.initials: L
authors.lastname: Baandrup
authors.forename: Mette T
authors.initials: MT
authors.lastname: Faber
authors.forename: Jane
authors.initials: J
authors.lastname: Christensen
authors.forename: Allan
authors.initials: A
authors.lastname: Jensen
authors.forename: Klaus K
authors.initials: KK
authors.lastname: Andersen
authors.forename: Søren
authors.initials: S
authors.lastname: Friis
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Kjaer
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D016588:Anticarcinogenic Agents / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use*; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D009361:Neoplasm Invasiveness; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000517:prevention & control; D012307:Risk Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016588:Anticarcinogenic Agents; D001241:Aspirin