The association between the polymorphisms of TNF-α and non-Hodgkin lymphoma: a meta-analysis

Many genetic variations in the promoter region of tumor necrosis factor alpha (TNF-α) may confer host susceptibility to cancer by influencing TNF-α expression. Nevertheless, the results remain inconclusive. The current meta-analysis was performed to investigate the association between three common TNF-α promoter polymorphisms and the risk of non-Hodgkin lymphoma (NHL). A literature search was conducted mainly from PubMed for all eligible studies. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to assess the association of TNF-α polymorphisms with the risk of NHL. TNF-α −308 A allele showed a statistically significant increased risk for NHL under the homozygous (AA vs. GG, OR = 1.51, 95 % CI = 1.26–1.80) and recessive (OR = 1.47, 95 % CI = 1.23–1.75) models, respectively. The stratified analyses showed an increased risk of NHL with the presence of TNF-α −308 A allele among Africans and Caucasians, but a decreased risk among Asians. No association was observed between −238 G/A polymorphism and NHL risk either in the overall analysis or in the stratified analysis. Similarly, pooled analysis did not reveal an altered risk of NHL with −857 C/T polymorphism. Nonetheless, a statistically significant association was observed among Asians when stratified by ethnicity. Among the three genetic variations of interest, TNF-α −308 G/A polymorphism was significantly associated with the risk of NHL; neither −238 G/A nor −857 C/T polymorphism was shown to alter the overall NHL risk; however, stratified analysis by ethnicity observed a statistically significant association between −857 C/T polymorphism and the risk of NHL among Asians.