title: Vitamin D receptor gene Tru9I polymorphism and risk for incidental sporadic colorectal adenomas.
abstract: OBJECTIVE
  Recent laboratory and epidemiological studies suggest that vitamin D is a potential agent for colorectal cancer prevention. Its function is partially mediated by the vitamin D receptor (VDR). The aim of this study was to investigate whether a novel G (allele "U") >A (allele "u") polymorphism (Tru9I) in the VDR intron 8 region is associated with risk for colorectal adenoma in a colonoscopy-based case-control study.
  
  
  METHODS
  Genotyping for a total of 391 subjects was carried out through PCR and restriction fragment length polymorphism.
  
  
  RESULTS
  The frequencies of "U" and "u" alleles were 89.3% and 10.7%, respectively. The "Uu" and "uu" genotypes were associated with decreased risk for adenoma (OR, 0.71; 95%CI, 0.40-1.25). The inverse association was more pronounced for multiple adenomas and adenomas that were larger had moderate or greater dysplasia, or were sessile: the odds ratios (ORs) were, 0.51 (95%CI, 0.21-1.24), 0.37 (95%CI, 0.11-1.28), 0.68 (95%CI, 0.33-1.41), and 0.36 (95%CI, 0.13-0.97) respectively. In joint/combined analyses, inverse associations were more obvious among those who had at least one "u" allele and also were younger (OR, 0.60; 95%CI, 0.26-1.37), women (OR, 0.38; 95%CI, 0.17-0.88), did not smoke (OR, 0.39; 95%CI, 0.13-1.23), or took NSAID (OR, 0.38; 95%CI, 0.12-1.25), but no evidence existed for interactions with calcium or vitamin D intake.
  
  
  CONCLUSIONS
  Our findings suggest that the VDR Tru9I polymorphism may be associated with lower risk for colorectal adenoma, particularly in interaction with various risk factors, but not with calcium or vitamin D.
authors.affiliation: Tumor Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China.
authors.forename: You-Ling
authors.initials: YL
authors.lastname: Gong
authors.forename: Da-Wen
authors.initials: DW
authors.lastname: Xie
authors.forename: Zong-Lin
authors.initials: ZL
authors.lastname: Deng
authors.forename: Roberd M
authors.initials: RM
authors.lastname: Bostick
authors.forename: Xi-Jiang
authors.initials: XJ
authors.lastname: Miao
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Zhang
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Gong
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000235:genetics*; D000428:Alcohol Drinking; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D018167:Receptors, Calcitriol