CCDN1 rs603965 polymorphism may serve as a genetic biomarker of brain tumor: A meta‐analysis of 5,769 subjects

INTRODUCTION: Some studies already tried to assess the associations between cyclin D1 (CCND1) polymorphisms and brain tumor. However, the results of these studies were not consistent. Thus, we performed the present meta‐analysis to explore the relationship between CCND1 polymorphisms and brain tumor in a larger pooled population. METHODS: PubMed, Web of Science, Embase, and CNKI were searched for related articles. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the potential associations. RESULTS: Totally nine studies with 5,769 subjects were analyzed. A significant association with brain tumor susceptibility was observed for the rs603965 polymorphism in GG versus GA + AA (dominant comparison, p = 0.003, OR = 0.72, 95% CI 0.57–0.89, I (2) = 64%), AA versus GG + GA (recessive comparison, p = 0.004, OR = 1.46, 95% CI 1.13–1.88, I (2) = 67%), and G versus A (allele comparison, p = 0.0004, OR = 0.77, 95% CI 0.66–0.89, I (2) = 66%) in overall population. Further subgroup analyses by ethnicity yielded similar positive results in both Asians and Caucasians. Moreover, in stratified analyses by type of disease, we noticed that the rs603965 polymorphism was significantly associated with the susceptibility to glioma, but such positive results were not detected in pituitary adenoma or meningioma. Additionally, a significant association with tumor grade was also observed for the rs603965 polymorphism in G versus A (allele comparison, p = 0.02, OR = 0.74, 95% CI 0.59–0.95, I (2) = 26%). CONCLUSIONS: Our findings suggested that CCND1 rs603965 polymorphism may serve as a potential genetic biomarker of brain tumor, especially for glioma.