Objective: Recently, a common insertion/deletion (-94insertion/deletion ATTG, rs28362491) polymorphism in the NFkB1 promoter region has been extensively investigated for association with cancer risk but the results have been inconsistent. In order to clarify the effect of the promoter polymorphism we performed an update meta-analysis of published case-control studies to better compare the results between studies.
Methods: Relevant studies were identified via a thorough literature search on Medline and Embase database (up to August 10, 2011). The odds ratio (OR) and 95% confidence interval (95%CI) were used to investigate the strength of the association.
Results: A total of 5,196 cases and 6,614 controls in 19 case-control studies from 16 publications were included in this meta-analysis. Overall, the variant genotypes were associated with a moderately decreased risk of all cancer types (OR =0.74, 95%CI =0.57-0.97 for DD versus II; OR =0.79, 95%CI =0.66-0.95 for DD versus II/ID). In the stratified analyses, significantly decreased risk was found among Asians (OR =0.52, 95%CI =0.42-0.65 for DD versus II; OR =0.74, 95%CI =0.66-0.83 for ID versus II; OR =0.64, 95%CI =0.53-0.78 for DD versus II/ID; OR =0.68, 95%CI =0.61-0.75 for DD/ID versus II). The validity of this association was further strengthened by the sensitivity analysis. No publication bias was observed in this study.
Conclusions: Our results suggested that the -94deletion ATTG promoter polymorphism in NFkB1 gene might be associated with a decreased cancer risk, especially for Asian population.