Supplementary Material for: Meta-Analysis Shows Strong Positive Association of the TNF-α Gene with Tumor Stage in Bladder Cancer

There is no consensus on the association between the tumor necrosis factor-α (TNF-α) gene promoter –308 A/G single nucleotide polymorphisms and bladder cancer risk. To obtain a more precise estimation of this correlation, we conducted a meta-analysis. The PubMed, MEDLINE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched for relevant published studies. Seven case-control studies with a total of 1,311 cases and 1,436 controls were identified and analyzed. A notable correlation was observed between the TNF-α genotype and bladder cancer grade (AA+GA vs. GG; odds ratio 1.96, 95% confidence interval 1.37–2.80, p = 0.0002). In summary, this meta-analysis demonstrates that the TNF-α –308 AA+GA genotype may be a marker to the tumor-invasive stage of bladder cancer.