Cyclin D1 G870A polymorphism and risk of nasopharyngeal carcinoma: a meta-analysis

Abstract

Recently, there have been a number of studies on the association between cyclin D1 G870A polymorphism and nasopharyngeal carcinoma risk. However, the results of previous reports remain controversial and ambiguous. Thus, we performed a meta-analysis to explore more precisely the association between cyclin D1 G870A polymorphism and the risk of nasopharyngeal carcinoma. No significant association was found between cyclin D1 G870A polymorphism and nasopharyngeal carcinoma risk in total population analysis. In the subgroup meta-analysis by ethnicity, a negative association was shown in Caucasian subgroup, and no significant association in any genetic models among Asians was observed. In summary, positive results have been shown on the search for polymorphic variants influencing the risk of NPC. This meta-analysis provides evidence of the association between CCND1 G870A polymorphism and NPC risk, supporting the hypothesis that CCND1 870A allele probably acts as an important NPC protective factor in Caucasians but not in Asians. Since the results of our meta-analysis are preliminary and may be biased by the relatively small number of subjects, they still need to be validated by well-designed studies using larger samples in the future.

Figure 1

Flow chart of study selection based on the inclusion and exclusion criteria.

Figure 2

Forest plots of cyclin D1 G870A polymorphism in nasopharyngeal carcinoma versus normal control and subgroup analyses for A genotype compared with G genotype. The squares and horizontal lines correspond to the study specific OR and 95% CI. The area of the squares reflects the weight (inverse of the variance). The diamond represents the summary OR and 95% CI. OR: odds ratio.

Figure 3

Forest plots of cyclin D1 G870A polymorphism in nasopharyngeal carcinoma versus normal control and subgroup analyses for AA genotype compared with GG genotype.

Figure 4

Forest plots of cyclin D1 G870A polymorphism in nasopharyngeal carcinoma versus normal control and subgroup analyses for GA genotype compared with GG genotype.

Figure 5

Forest plots of cyclin D1 G870A polymorphism in nasopharyngeal carcinoma versus normal control and subgroup analyses for AA + GA genotype compared with GG genotype.