title: Chemopreventive effect of nonsteroidal anti-inflammatory drugs on the development of a new colorectal polyp or adenoma in a high-risk population: a meta-analysis.
abstract: BACKGROUND
  Although many experimental, epidemiologic, and clinical studies have suggested that aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in reducing and preventing colorectal adenomas, randomized, controlled trials (RCTs) are still being carried out to obtain statistically reliable results.
  
  
  OBJECTIVE
  The aim of this meta-analysis was to review long-term, prospective RCTs investigating the effect of NSAIDs on the relative risk (RR) for developing ≥1 new colorectal polyp or adenoma in a high-risk population.
  
  
  METHODS
  We conducted a comprehensive search of MEDLINE, PubMed, and other electronic databases (including Inter-Science, Science Direct, Ebsco, Synergy, and Proquest) (key terms: nonsteroidal anti-inflammatory drugs, aspirin, colorectal, and polyps; years: 1974-2004) for English-language articles. Eligible studies were analyzed in terms of demographic data, adverse effects, and effect of NSAIDs on the RRs.
  
  
  RESULTS
  Four long-term, prospective RCTs were used in the statistical analysis. A total of 2069 high-risk patients were enrolled; 1880 patients completed the studies, and 1127 were in active-treatment groups (aspirin 81-325 mg/d or sulindac 150-300 mg/d). Our meta-analysis of these studies revealed that the overall RR for developing ≥ 1 new colorectal polyp or adenoma was significantly reduced by using aspirin or other NSAIDs (RR = 0.809; 95% CI, 0.718-0.912).
  
  
  CONCLUSIONS
  The results of this meta-analysis suggest that regular use of aspirin 81 to 325 mg/d or sulindac 150 to 300 mg/d for ≥1 year was associated with a decrease in the RR for developing ≥ 1 new colorectal polyp or adenoma to 0.80 (95% CI, 0.718-0.912) in patients at high risk.
authors.affiliation: Department of Biostatistics, Mersin University, Mersin, Turkey.
authors.forename: Emine Arzu
authors.initials: EA
authors.lastname: Kanik
authors.affiliation: Department of General Surgery, Mersin University, Mersin, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Canbaz
authors.affiliation: Department of General Surgery, Mersin University, Mersin, Turkey.
authors.forename: Tahsin
authors.initials: T
authors.lastname: Colak
authors.affiliation: Department of General Surgery, Mersin University, Mersin, Turkey.
authors.forename: Suha
authors.initials: S
authors.lastname: Aydin
keywords: NSAIDs; aspirin; colorectal adenoma; colorectal cancer; meta-analysis; relative risk