title: Meta-Analysis of ABCB1 3435C>T Polymorphism and Colorectal Cancer.
abstract: OBJECTIVE
  Many studies have focused on the association between the ABCB1 3435C>T polymorphism and colorectal cancer (CRC) risk. However, the results were conflicting. The aim of this meta-analysis is to evaluate the precise association between this polymorphism and CRC risk.
  
  
  METHODS
  We formally reviewed the literature at Pubmed, EMBASE and the Cochrane Library with the key words as follows: ABCB1/MDR1/P-glycoprotein, polymorphism, colorectal and cancer/neoplasm/tumor. This meta-analysis was assessed by Review manager 5.0. The fixed-effects model was used to pool the odds ratios (OR) with 95% confidence intervals (CI) for CRC risk.
  
  
  RESULTS
  There were 8 studies identified. The pooled OR with 95% CI of CC+CT versus TT genotype of the ABCB1 3435C>T polymorphism for CRC risk was 1.01 [0.90-1.13]. The sensitivity analysis further confirmed the result. Heterogeneity and publication bias were not observed in this meta-analysis.
  
  
  CONCLUSIONS
  In summary, there was no significant association between the ABCB1 3435C>T polymorphism and CRC risk. Abbreviations used: the ATP-binding cassette, subfamily B, member 1 (ABCB1); multidrug resistance gene 1 (MDR1); P-glycoprotein (P-gp); colorectal cancer (CRC); single nucleotide polymorphisms (SNPs); odds ratio (OR); confidence interval (CI); Hardy-Weinberg equilibrium (HWE).
authors.affiliation: Dan Zhang, Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, No. 37 on Guoxue Xiang, Chengdu, Sichuan Province, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Cun Wang, Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, No. 37 on Guoxue Xiang, Chengdu, Sichuan Province, China.
authors.forename: Cun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Zongguang Zhou Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, No. 37 on Guoxue Xiang, Chengdu, Sichuan Province, China.
authors.forename: Zongguang
authors.initials: Z
authors.lastname: Zhou
keywords: ABCB1; Colorectal cancer; MDR1; Meta-analysis; P-gp; Polymorphism