Association between macrophage migration inhibitory factor promoter region polymorphism (-173 G/C) and cancer: a meta-analysis

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine upstream of many inflammatory cytokines. MIF is implicated in several acute and chronic inflammatory conditions. MIF's promoter region has functional single nucleotide polymorphisms that controls MIF expression and protein levels. Since increased plasma MIF levels are associated with cancer, studies have examined the association between Mif promoter polymorphisms and cancer. This study is a meta-analysis of the available studies on such an association. RESULTS: A total of 5 studies were included in this meta-analysis to include 1116 cases (cancer patients) and 1728 controls (no cancer). Carrying any C allele in the Mif -173 G/C promoter polymorphism resulted in a significantly greater risk for developing cancer [OR = 1.89 (1.15-3.11), p = 0.012)] when compared to the (G/G) genotype. Subgroup analysis revealed that this association was significant only for "solid" tumors (including gastric and prostate cancers) [OR = 2.67 (1.26-5.65), p = 0.010] but not for "non-solid" tumors (leukemia) [OR = 1.21 (0.95-1.55), p = 0.122]. Furthermore, when only prostate tumor studies were included in the analysis, the association became even stronger [OR = 3.72 (2.55-5.41), p < 0.0001]. CONCLUSIONS: Meta-analysis suggests there is an association between any C allele in the Mif -173 G/C promoter polymorphism and an increased risk of cancer, particularly for solid tumors. The association appeared stronger for prostate cancer, specifically. Future studies that include different types of cancers are needed to support and extend these observations.