Tumor Necrosis Factor α −308 G>A Polymorphisms and Cervical Cancer Risk

Abstract

Tumor necrosis factor α (TNF-α), secreted mainly by activated macrophages, is recently involved in fighting against tumorigenesis. Tumor necrosis factor α -308 G>A, the common polymorphism in the promoter of TNF-α, has been implicated to alter the risk of cervical cancer, yet the results of relative studies are inconclusive or controversial. To derive a more precise estimation of the relationship, we performed a meta-analysis based on 8 studies. A comprehensive search was conducted to examine all the eligible studies of TNF-α -308 G>A polymorphism and cervical cancer risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Eight studies regarding TNF-α -308 G>A polymorphism status including 2298 cases and 1903 controls were collected. Overall, significantly elevated cervical cancer risk was found for A allele versus G allele (OR, 1.25; 95% CI, 1.10-1.42), for GA versus GG (OR, 1.33; 95% CI, 1.14-1.54), and for GA/AA versus GG (OR, 1.31; 95% CI, 1.14-1.52). In the subgroup analysis by ethnicity, significantly increased risks were also found among whites (for A allele vs G allele: OR, 1.16; 95% CI, 1.00-1.34; for GA vs GG: OR, 1.24; 95% CI, 1.05-1.48; and for GA/AA vs GG: OR, 1.22; 95% CI, 1.03-1.44) and Asians (for A allele vs G allele: OR, 2.36; 95% CI, 1.60-3.50; AA vs GG: OR, 3.85; 95% CI, 1.30-11.37; for GA vs GG: OR, 2.06; 95% CI, 1.30-3.27; GA/AA vs GG: OR, 2.29; 95% CI, 1.49-3.52; and for AA vs OR, 3.70; 95% CI, 1.25-10.81). However, no significant associations were found among Africans for all genetic models. The natural genetic polymorphism in TNF-α -308 G>A is a risk factor for developing cervical cancer, especially for Asians and whites.