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

The -889 C/T polymorphism in the interleukin-1 alpha (IL-1 alpha) 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(TM), Web of Science(TM), Science Direct(R), SpringerLink, EBSCO, Wanfang, and Chinese National Knowledge Infrastructure (CNKI) databases was carried out to identify studies investigating the association between IL-1 alpha -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-1 alpha -889 C/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-1 alpha -889 C/T polymorphism contributes to cancer susceptibility. Further large and well-designed studies are needed to confirm this association.