Association between cyclin D1 G870A polymorphism and hepatocellular carcinoma risk: a meta-analysis

Background: Cyclin D1 (CCND1) G870A polymorphism may be associated with hepatocellular carcinoma (HCC) risk, but the results of previous studies were inconsistent. Available evidence was meta-analyzed to assess their potential association. Methods: Databases PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature database, China National Knowledge Infrastructure, and Google Scholar were systematically searched. Meta-analyses were performed to investigate the association of G870A polymorphism with HCC risk by calculating odds ratios (ORs) and 95% confidence intervals (CIs) from the data of relevant case-control studies. Results: Results of this meta-analysis of six case-control studies involving 1,030 cases and 1,683 controls indicate that G870A polymorphism was not associated with HCC risk in any of the five genetic models tested (recessive model: AA vs GG + AG: OR = 1.38, 95% CI = 0.95-2.00, P = 0.09; dominant model: AG + AA vs GG: OR = 1.38, 95% CI = 0.87-2.20, P = 0.17; homozygous model: AA vs GG: OR = 1.60, 95% CI = 0.87-2.94, P = 0.13; heterozygous model: AG vs GG: OR = 1.24, 95% CI = 0.86-1.79, P = 0.25; allelic model: A vs G: OR = 1.30, 95% CI = 0.95-1.80, P = 0.10). Subgroup analyses according to ethnicity showing marginally significant association between this single nucleotide polymorphism and HCC risk indicate that G870A may be significantly associated with HCC risk in Caucasian populations (recessive model: AA vs GG + AG: OR = 2.34, 95% CI = 1.60-3.42, P<0.0001; dominant model: AG + AA vs GG: OR = 2.44, 95% CI = 1.19-4.97, P = 0.01; homozygous model: AA vs GG: OR = 3.42, 95% CI = 1.80-6.50, P = 0.0002; allelic model: A vs G: OR = 2.06, 95% CI = 1.31-3.24, P = 0.002), but not in Asian populations. Conclusion: Available evidence suggests that no significant association between G870A polymorphism and HCC risk was found in either total populations or Asian populations. However, significant association was found in Caucasian populations. These results should be verified and extended in further detailed and well-designed studies involving larger, multiethnic samples.