title: Non-steroidal anti-inflammatory drug use and the risk of gastric cancer: a systematic review and meta-analysis.
abstract: BACKGROUND
  The relationship between the use of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, and the risk of gastric cancer has not been well studied. We performed a systematic review and meta-analysis of published studies to evaluate the association between use of this class of drugs and the risk of gastric cancer.
  
  
  METHODS
  A fully recursive literature search to January 2003 was conducted in MEDLINE, PubMed, and CANCERLIT to identify potentially relevant case-control or cohort studies. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated under a random-effects model.
  
  
  RESULTS
  Nine studies (eight case-control and one cohort) with a total of 2831 gastric cancer case patients were identified. NSAID use was associated with a reduced risk of gastric cancer, with a summary odds ratio of 0.78 (95% CI = 0.69 to 0.87). Users of aspirin (OR = 0.73, 95% CI = 0.63 to 0.86) and non-aspirin NSAIDs (OR = 0.74, 95% CI = 0.55 to 1.00) experienced similar magnitudes of risk reduction. Regular users of NSAIDs (OR = 0.57, 95% CI = 0.44 to 0.74) experienced a lower risk of gastric cancer relative to nonusers than did irregular users (OR = 0.76, 95% CI = 0.62 to 0.94; P =.09 versus regular users). A stratified analysis showed that NSAID use was associated with a statistically significant reduction in risk of noncardia gastric cancer (OR = 0.72, 95% CI = 0.58 to 0.89), but not of gastric cancer at the cardia (OR = 0.80, 95% CI = 0.53 to 1.20). There was no evidence that study design or type of control subject substantially influenced the estimate of effects.
  
  
  CONCLUSIONS
  NSAID use was associated with a decreased risk of gastric cancer in a dose-dependent manner. This finding warrants proper clinical trials in populations with high risk of gastric cancer.
authors.affiliation: Department of Gastroenterology, First Hospital, Peking University, Beijing, China.
authors.forename: Wei Hong
authors.initials: WH
authors.lastname: Wang
authors.forename: Jia Qing
authors.initials: JQ
authors.lastname: Huang
authors.forename: Ge Fan
authors.initials: GF
authors.lastname: Zheng
authors.forename: Shiu Kum
authors.initials: SK
authors.lastname: Lam
authors.forename: Johan
authors.initials: J
authors.lastname: Karlberg
authors.forename: Benjamin Chun-Yu
authors.initials: BC
authors.lastname: Wong
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000494:pharmacology*; D016588:Anticarcinogenic Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D002299:Cardia; D016022:Case-Control Studies; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori; D006801:Humans; D015994:Incidence; D016017:Odds Ratio; D012107:Research Design; D018570:Risk Assessment; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016588:Anticarcinogenic Agents