Association Between VDR BsmI Polymorphism And Colorectal Cancer Risk: An Updated Meta-Analysis

Objective: Bsm I is a site of extensive research of the vitamin D receptor gene.At present,there are many overseas studies on the relationship between the Bsm I locus and the susceptibility to colorectal cancer.However,due to the different sample sizes and racial differences,the relationship between polymorphism of vitamin D receptor gene and the susceptibility to colorectal cancer There is still much controversy.In order to reduce the bias between studies and improve the statistical validity,this study used meta-analysis to determine whether the Bsm I site of vitamin D receptor gene was related to the development of colorectal cancer and analyzed the results.Methods: Computer searches of the Pubmed database of the National Library of Medicine,EMBASE,Medline,Embase,CNKI database,Sino Med,Wanfang database,VIP.Retrieval time ended in October 2017 at home and abroad publicly published on the VDR Bsm I site genetic polymorphism and genetic susceptibility to colorectal cancer in the case-control study of the literature.After independently screening the literature by two investigators,extracting data and assessing the risk of inclusion in the study.The included literature was heterogeneously examined using Review Manager 5.3.3software and the combined odds ratio(OR)and its 95% CI.Results: A total of ten case-control studies were included,with a total sample number of 8464 cases in the final case group and 9037 cases in the control group.Meta-analysis showed that in the comparison of alleles B and b,the P value of the heterogeneity test was less than 0.00001 and I2= 90%.The random effect model was used,OR = 0.93,95% CI = 0.93(0.84-1.04),P = 0.20,indicating that the allele B and b between the cause of colorectal cancer was no significant difference;dominant model(BB + Bb vs bb),the heterogeneity test P value was 0.46,I2 = 0%,with a fixed effect model,OR =0.92,95% CI: 0.86-0.98,P = 0.009,the difference was statistically significant,indicating that dominant gene promulgated significant effect on the occurrence of colorectal cancer.In the recessive model(BB vs Bb + bb),the P value of the heterogeneity test was 0.54 and I2= 0%.The fixed effect model was used.OR = 0.92,95% CI: 0.85-1.00,P = Significance of learning.In addition,the P value of heterogeneity test was 0.72 and I2= 0% in BB genotype compared with bb genotype.The fixed effect model was used,OR = 0.89,95% CI: 0.81-0.97,P = 0.01,the difference was Statistical significance.In the comparison between Bb genotype and bb genotype,the heterogeneity test had a P value of 0.21 and I2 = 25%,with a fixed effect model,OR = 0.93,95% CI: 0.87-0.99,P = 0.03,and the difference was statistically significant.Conclusion: Vitamin D receptor gene Bsm I may increase the risk of colorectal cancer,especially in white populations in countries such as the United States and Europe.