Cyclin D1 G870A polymorphism is associated with risk and clinicopathologic characteristics of bladder cancer

Cyclin D1 (CCND1) is a key protein in regulation of cell cycle at the G1-to-S transition phase and is essential for regulation of cell proliferation, differentiation, and transcriptional control. We hypothesized that the CCND1 G870A polymorphism is associated with risk of bladder cancer. The CCND1 G870A polymorphism was genotyped in a hospital-based case-control study of 402 bladder cancer cases and 402 control subjects using the polymerase chain reaction-restriction fragment length polymorphism method. Unconditional univariate and multivariate logistic regression analyses were used to evaluate the associations between the CCND1 G870A polymorphism and bladder cancer risk. A significantly increased risk of bladder cancer was associated with the combined variant CCND1 870GA/AA genotypes (adjusted odds ratio, 1.54; 95% confidence interval, 1.08-2.20) compared with the GG genotype, particularly among subgroups of age ≥65 years (1.74; 1.06-2.88), men (1.67; 1.15-2.44), and smokers (1.82; 1.12-2.93). Further, the G870A polymorphism was significantly associated with risk of developing superficial bladder cancer (grade 1). In addition, a meta-analysis of the G870A polymorphism and bladder cancer risk showed that the variant 870GA/AA genotypes were associated with an increased risk of bladder cancer in Asians, but not in Caucasians, which was consistent with the results of our study. The CCND1 G870A polymorphism may be a marker for the development of bladder cancer in Chinese populations. Larger studies are required to validate these findings in diverse populations.