title: Vitamin D receptor BsmI polymorphism and colorectal cancer risk: an updated analysis.
abstract: BACKGROUND
  Previous studies have investigated the association between the vitamin D receptor (VDR) BsmI polymorphism and colorectal cancer (CRC) susceptibility, but the results were conflicting. The aim of this study is to quantitatively summarize the relationship between this polymorphism and CRC risk.
  
  
  METHODS
  Two investigators independently searched the Medline, Embase, China National Knowledge Infrastructure (CNKI) and Chinese Biomedicine databases for studies published before November 2013. Summary odds ratios (ORs) and 95% confidence intervals (95%CIs) for VDR BsmI polymorphism and CRC were calculated in a fixed- effects model (the Mantel-Haenszel method) and a random-effects model (the DerSimonian and Laird method) when appropriate.
  
  
  RESULTS
  This meta-analysis included 14 case-control studies, which included 10,822 CRC cases and 11,779 controls. Overall, the variant genotype (BB) of the BsmI was associated with a lower CRC risk when compared with the wild-type bb homozygote (OR=0.66, 95%CI: 0.49-0.88). Similarly, a decreased CRC risk was also found in the dominant and recessive models. When stratifying for ethnicity, source of controls, and study sample size, associations were observed among Caucasians, population-based studies and studies with large study sample size (>1000 subjects). Limiting the analysis to the studies within Hardy-Weinberg equilibrium, the results were persistent and robust. No publication bias was found in the present study.
  
  
  CONCLUSIONS
  This updated meta-analysis suggests that the VDR BsmI polymorphism may be associated with a moderate protective effect against CRC.
authors.affiliation: Institute of Stem Cell and Developmental Biology, West China Second Hospital, Sichuan University, Chengdu, China E-mail : hxluqing@163.com.
authors.forename: Kun
authors.initials: K
authors.lastname: Yu
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Run
authors.initials: R
authors.lastname: Song
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
mesh_terms: D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D015201:Meta-Analysis as Topic; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D018167:Receptors, Calcitriol / Q000235:genetics*; D012307:Risk Factors
chemical_list: D018167:Receptors, Calcitriol; C053864:endodeoxyribonuclease BsmI; D015252:Deoxyribonucleases, Type II Site-Specific