IL-1α -889 C/T polymorphism and cancer susceptibility: a meta-analysis.

The -889 C/T polymorphism in the interleukin-1α (IL-1α) gene has been implicated in the risk of cancer, but the results are inconclusive. The present meta-analysis aimed to investigate the association between the -889 C/T polymorphism and cancer risk. A literature search in PubMed, Embase™, Web of Science™, Science Direct(®), SpringerLink, EBSCO, Wanfang, and Chinese National Knowledge Infrastructure (CNKI) databases was carried out to identify studies investigating the association between IL-1α -889 C/T polymorphism and cancer risk. The odds ratio (OR) with 95% confidence interval (CI) were used to assess the strength of association. A total of 20 publications, involving 6,782 cases and 7,767 controls, were included in this meta-analysis. Combined analysis revealed a significant association between -889 C/T polymorphism and cancer risk under an allele model (OR =1.12, 95% CI =1.02-1.24, P=0.02), recessive model (OR =1.34, 95% CI =1.06-1.68, P=0.01), and homozygous comparison (OR =1.38, 95% CI =1.10-1.74, P<0.01). Subgroup analysis by ethnicity showed there was significant association between cancer risk and IL-1α -889C/T polymorphism in Asian populations under a recessive model (OR =2.57, 95% CI =1.11-5.98, P=0.03) and homozygous comparison (OR =2.60, 95% CI =1.12-6.04, P=0.03). Moreover, a subgroup analysis was conducted by source of control, and a statistically increased cancer risk was found in the hospital-based group, under a recessive model (OR =1.62, 95% CI =1.03-2.56, P=0.04) and homozygous comparison (OR =1.67, 95% CI =1.04-2.68, P=0.03). This meta-analysis suggests that IL-1α -889 C/T polymorphism contributes to cancer susceptibility. Further large and well-designed studies are needed to confirm this association.