title: Association between CTLA-4 rs231775 polymorphism and risk of colorectal cancer: a meta analysis.
abstract: OBJECTIVE
  Many previous studies that examined the association between CTLA-4 rs231775 polymorphism and CRC risk have produced inconsistent results. In this study, a meta-analysis was performed to systematically summarize the possible association.
  
  
  METHODS
  We identified relevant studies using PubMed, Embase, and China National Knowledge Infrastructure literature databases. Eligible studies were selected using specific criteria. Data were extracted independently by two authors. The pooled OR with 95% CI was estimated by applying the fixed-effects model to examine the association of interest.
  
  
  RESULTS
  Eight studies were identified for the meta-analysis. In overall analysis, we observed an significantly increased CRC risk attributed to the AG genotype as compared to the AA genotype (OR: 1.17, 95% CI: 1.02-1.35 for AG vs AA). Stratified analysis according to ethnicity also showed a significant association in Caucasians under the AG vs AA model (OR: 1.22, 95% CI: 1.03-1.46). No significant heterogeneity or publication bias was tested in our meta-analysis.
  
  
  CONCLUSIONS
  In conclusion, the meta-analysis suggests that rs231775 in the CTLA-4 gene may be a risk factor for CRC, especially in Caucasians.
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Jing
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Su
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Shunchang
authors.initials: S
authors.lastname: Jiao
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Oncology, Chinese PLA General Hospital, PLA Medical School No 28 Fuxing Road, Haidian District, Beijing 100853, China.
authors.forename: Li
authors.initials: L
authors.lastname: Bai
keywords: CRC; CTLA-4; polymorphism; risk; rs231775