title: Hepatitis B virus infection is associated with gastric cancer in China: an endemic area of both diseases.
abstract: BACKGROUND
  Hepatitis B virus (HBV) infection was demonstrated to be a risk factor of several cancers of the digestive system. In addition, liver cirrhosis, which could possibly result from chronic HBV infection, was associated with a higher risk of gastric cancer. However, the association of HBV infection and gastric cancer has not been investigated.
  
  
  METHODS
  A retrospective case-control study with 580 cases and 580 controls matched for age, sex and year of diagnosis was conducted. The associations between gastric cancer and HBV infection were explored with univariate and multivariate unconditional logistic regression analysis.
  
  
  RESULTS
  Hepatitis B surface antigen (HBsAg) was positively associated with gastric cancer (AOR (95% CI): 1.49 (1.06-2.10)). This association remained significant in patients without family history of gastric cancer (AOR (95% CI): (1.06-2.11)). For HBsAg-negative population, being anti-HBc positive/anti-HBs negative, which possibly indicated occult HBV infection, was also found to have some associations with gastric cancer. In addition, some synergistic effects between HBV infection and blood type A in gastric cancer were identified.
  
  
  CONCLUSIONS
  The HBV infection was positively related with gastric cancer, especially for patients without family history of gastric cancer. Further prospective studies are warranted to confirm this relationship.
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: X-L
authors.initials: XL
authors.lastname: Wei
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: M-Z
authors.initials: MZ
authors.lastname: Qiu
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Y-X
authors.initials: YX
authors.lastname: Huang
authors.affiliation: Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: R-Y
authors.initials: RY
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: W-W
authors.initials: WW
authors.lastname: Chen
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: D-S
authors.initials: DS
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: H-Y
authors.initials: HY
authors.lastname: Luo
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: D-S
authors.initials: DS
authors.lastname: Zhang
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: F-H
authors.initials: FH
authors.lastname: Wang
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Li
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: R-H
authors.initials: RH
authors.lastname: Xu
mesh_terms: D000017:ABO Blood-Group System; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D019353:Endemic Diseases; D005260:Female; D006515:Hepatitis B virus / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000097:blood / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000821:virology*
chemical_list: D000017:ABO Blood-Group System