CCND1 G870A polymorphism and colorectal cancer risk: An updated meta-analysis

Molecular epidemiological studies have revealed a closer association between cyclin D1 (CCND1) polymorphism and the risk of colorectal cancer; however, the results were inconsistent. The aim of the present meta-analysis was to investigate the association between CCND1 G870A polymorphism and colorectal cancer risk. Online electronic databases (PubMed and Embase) were searched. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association between CCND1 G870A polymorphism and the risk of colorectal cancer. In addition, heterogeneity, publication bias and sensitivity analysis were performed to guarantee the statistical power. In total, 23 published case-control studies with 6,320 patients and 8,252 controls were selected. Significantly increased risks were observed in four genetic models (A vs. G: OR=1.09, 95% CI=1.00-1.18, I²=54.3%; GA vs. GG: OR=1.13, 95% CI=1.04-1.24, I²=18.2%; AA vs. GG, OR=1.17: 95% CI=1.00-1.38, I²=52.5%; GA+AA vs. GG: OR=1.14, 95% CI=1.05-1.24, I²=33.8%). Similarly, significant associations were also identified in the stratified analysis in the cancer subtype of sporadic colorectal cancer (GA vs. GG: OR=1.21, 95% CI=1.04-1.42, I²=24.1%; GA+AA vs. GG: OR=1.18, 95% CI=1.02-1.37, I²=35.0%), Caucasian population (GA vs. GG, OR=1.14, 95% CI=1.02-1.28, I²=19.8%; GA+AA vs. GG, OR=1.14, 95% CI=1.02-1.27, I²=37.5%) and other subgroups of control design and genotyping type. The present updated meta-analysis suggested that CCND1 G870A may present an increased risk for developing colorectal cancer, particularly in sporadic colorectal cancer and a Caucasian population.