Association between IL-6-174G>C polymorphism and risk of prostate cancer: a meta-analysis

The IL-6-174G>C polymorphism was the most common polymorphism that could directly affect the levels of IL-6. Previous studies have investigated the association between IL-6-174G>C polymorphism and the risk of prostate cancer (PCa), but the results remained controversial. The current study was designed to comprehensively clarify the association between IL-6-174G>C polymorphism and PCa susceptibility by the means of meta-analysis. A total of 12 studies from 10 articles with 12,626 cases and 14,672 controls were included in the meta-analysis. Pooled odd ratio (OR) with 95% confidential intervals (95% CI) were calculated to assess the summary effects. Subgroup analysis stratified by ethnicity and source of control were performed. The results showed that there was no association between IL-6-174G>C polymorphism and PCa risk under all five genetic models: CC vs GG: OR=1.11, 95% CI=0.92-1.33, P-h=0.002; GC vs GG: OR=1.02, 95% CI=0.97-1.08, P-h=0.253; CC+GC vs GG: OR=1.06, 95% CI=0.95-1.18, P-h=0.027; CC vs GC+GG: OR=1.07, 95% CI=0.92-1.24, P-h=0.008; and Aelle C vs Aelle G: OR=1.04, 95% CI=0.95-1.14, P-h=0.001. Subgroup analysis showed significantly elevated risk in hospital-based populations (CC vs GG: OR=1.2, 95% CI=1-1.44, P-h=0.699). Our meta-analysis suggested that IL-6-174G>C polymorphism may not be a risk factor for prostate cancer.