Association between Cyclin D1 polymorphism and oral cancer susceptibility: a meta-analysis

Data from several case-control studies on the relation between the Cyclin D1 (CCND1) G870A polymorphism and oral cancer susceptibility implicated conflicting conclusions. Thus, a meta-analysis was performed to derive a more precise evaluation of the association. We searched PubMed and Embase for related studies that had been published in English and eight available studies were finally included in the meta-analysis. Odd ratios (ORs) and 95 % confidence intervals (CIs) were calculated for each study. Our meta-analysis suggested that CCND1 G870A polymorphism was not associated with oral cancer risk (OR AA vs. GG = 1.08, 95 % CI = 0.90-1.30, P heterogeneity = 0.175; OR AA + GA vs. GG = 1.02, 95 % CI = 0.91-1.14, P heterogeneity = 0.781; OR AA vs. GA + GG = 1.16, 95 % CI = 0.98-1.36, P heterogeneity = 0.107; OR A vs. G = 1.05 95 % CI = 0.96-1.15, P heterogeneity = 0.211; OR GA vs. GG = 0.94, 95 % CI = 0.82-1.08, P heterogeneity = 0.935). However, in the subgroup analysis by ethnicity, possible significance among Asian groups was indicated in two genetic models (OR AA vs. GA + GG = 1.27, 95 % CI = 1.05-1.54, P heterogeneity = 0.572; OR allele A vs. allele G = 1.11, 95 % CI = 1.00-1.24, P heterogeneity = 0.211). Taken together, the meta-analysis revealed that CCND1 G870A polymorphism might be correlated with the susceptibility of oral cancer in Asians.