title: Red meat consumption and stomach cancer risk: a meta-analysis.
abstract: OBJECTIVE
  The association of red meat consumption with the risk of stomach cancer has been reported by many studies, with inconclusive results. We performed a meta-analysis of cohort and case-control studies to provide a quantitative assessment of this association.
  
  
  METHODS
  Relevant studies were identified by searching PubMed and Embase before December 2013 without restrictions. A total of 18 studies involving 1,228,327 subjects were included in this meta-analysis. Summary relative risks were estimated using random effects models.
  
  
  RESULTS
  The pooled relative risks of gastric cancer were 1.37 (95 % CI 1.18-1.59) for the highest versus lowest categories of red meat intake with significant heterogeneity among studies (P(heterogeneity) < 0.001, I(2) = 67.6 %). When stratified by the study design, the significant associations were observed in population-based case-control studies (RR 1.58; 95 % CI 1.22-2.06; P(heterogeneity) < 0.001, I(2) = 73.0 %) and hospital-based case-control studies (RR 1.63; 95 % CI 1.38-1.92; P(heterogeneity) = 0.284, I(2) = 19.1 %). However, no association was observed among cohort studies (RR 1.00; 95 % CI 0.83-1.20; P(heterogeneity) = 0.158, I(2) = 33.9 %). The significant association was also presented in the subgroup analysis by geographic area (Asia, Europe), publication year (≥2000), sample size (<1,000, ≥1,000) and quality score (<7 stars, ≥7 stars). The dose-response analysis associated every 100 g/day increment in red meat intake with a 17 % increased gastric cancer risk (RR 1.17; 95 % CI 1.05-1.32). A linear regression model further revealed that the risk of gastric cancer increased with increasing level of red meat consumption.
  
  
  CONCLUSIONS
  Increased intake of red meat might be a risk factor for stomach cancer. Further larger prospective studies are warranted to verify this association.
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Nanjing Medical University, 121 Jiangjiayuan Road, Nanjing, 210011, China, pengsong90@126.com.
authors.forename: Peng
authors.initials: P
authors.lastname: Song
authors.forename: Ming
authors.initials: M
authors.lastname: Lu
authors.forename: Qin
authors.initials: Q
authors.lastname: Yin
authors.forename: Lei
authors.initials: L
authors.lastname: Wu
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Fu
authors.forename: Baolin
authors.initials: B
authors.lastname: Wang
authors.forename: Qinghong
authors.initials: Q
authors.lastname: Zhao
mesh_terms: D016022:Case-Control Studies; D004032:Diet; D006801:Humans; D008460:Meat / Q000009:adverse effects*; D011379:Prognosis; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology*