Association of polymorphisms in the MCP-1 and CCR2 genes with the risk of cancer: a meta-analysis.
Studies investigating the impact of polymorphisms on monocyte chemotactic protein-1 (MCP-1) and CC chemokine receptor 2 (CCR2) on the risk of cancer have reported inconsistent results. We performed a meta-analysis of 23 eligible studies to summarize the data describing the association between cancer risk and polymorphisms in MCP-1 A2518G and CCR2 V64I. Q-statistics and I(2) statistics were calculated to examine heterogeneity and summary odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated using a random effects model. Potential sources of heterogeneity were investigated via subgroup and sensitivity analyses, and publication biases were estimated. Overall, MCP-1 and CCR2 polymorphisms showed no significant associations with cancer risk (MCP-1-2518A/G, GG + GA vs. AA: OR=0.94, 95% CI=0.76-1.17; CCR2 V64I, AA+AG vs. GG: OR=1.27, 95% CI=0.87-1.86). However, strong evidence of heterogeneity was found among the investigated studies, and subgroup analyses were therefore conducted according to study location, cancer type, source of controls, and presence of deviation from the Hardy-Weinberg equilibrium (HWE). When the data were stratified by study location, the increased risk of cancer among A allele carriers of CCR2 V64I was observed only in studies conducted in Asian countries (AA+AG vs. GG: OR=1.65; 95% CI=1.25-2.18). This meta-analysis suggests that genetic polymorphisms of CCR2 V64I may influence the susceptibility of cancer in Asian countries. Further well-designed studies with larger sample sizes should be conducted.