title: Interactions between pork consumption, CagA status and IL-1B-31 genotypes in gastric cancer.
abstract: OBJECTIVE
  To explore potential interactions among Helicobacter pylori (H. pylori), CagA status, interleukin (IL)-1B-31 genotypes, and non-cardiac gastric cancer (GC) risk.
  
  
  METHODS
  A case-control study of non-cardia GC was performed at 3 hospitals located in Xi'an, China, between September 2008 and July 2010. We included 171 patients with histologically diagnosed primary non-cardia GC and 367 population based controls (matched by sex, age and city of residence). A standardized questionnaire was used to obtain information regarding potential risk factors, including pork consumption. H. pylori CagA status was assessed by enzyme-linked immunosorbent assay, and IL-1B-31 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. Multivariate unconditional logistic regression was used to explore potential interactions among the factors.
  
  
  RESULTS
  The CagA appeared to confer an increased risk of GC (OR = 1.81, 95%CI: 1.25-2.61). The main associations with IL-1B-31C allele here were 0.98 (95%CI: 0.59-1.63) for CC vs TT and 0.99 (95%CI: 0.64-1.51) for C Carriers vs TT. However, no associations were observed for CagA or IL-1B-31 genotype status among subjects who reported low pork consumption (P for interaction = 0.11). In contrast, high pork consumption and IL-1B-31C genotypes appeared to synergistically increase GC risk (P for interaction = 0.048) after adjusting for confounding factors, particularly among subjects with CagA (OR = 3.07, 95%CI: 1.17-10.79). We did not observe effect modification of pork consumption by H. pylori CagA status, or between H. pylori CagA status and IL-1B-31 genotypes after adjustment for pork consumption and other factors.
  
  
  CONCLUSIONS
  These interaction relationships among CagA, IL-1B-31 and pork consumption may have implications for development of the preventive strategies for the early detection of non-cardiac GC.
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Xiao-Qin
authors.initials: XQ
authors.lastname: Wang
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Terry
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Li
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yan
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Jian-Sheng
authors.initials: JS
authors.lastname: Wang
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Wen-An
authors.initials: WA
authors.lastname: Wu
authors.affiliation: Xiao-Qin Wang, Hong Yan, Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Sen-Ke
authors.initials: SK
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002681:China; D004032:Diet / Q000009:adverse effects*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D008460:Meat / Q000009:adverse effects*; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000209:etiology* / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D011795:Surveys and Questionnaires; D013552:Swine
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; C508585:IL1B protein, human; D053583:Interleukin-1beta; C080866:cagA protein, Helicobacter pylori
keywords: CagA; Gastric cancer; Helicobacter pylori; Interaction; Pork; interleukin-1B