Impact of MDM2 309T>G polymorphism on sarcomagenesis

Background: A series of epidemiological studies have attempted to evaluate the impact of 309T>G polymorphism in MDM2 gene frequently identified as a susceptibility loci for various cancers on malignant sarcomas, however the reported conclusions remain inconsistent and elusive. We pooled all usable data sets in order to systematically assess the association between 309T>G polymorphism and sarcoma risk. Methods: To identify as many informative studies with complete data as possible, we searched a number of databases (PubMed, EBSCO, BIOSIS, the Cochrane Library, ISI Web of Science, Wiley Online Library and Embase). Inclusion criteria were defined to select the eligible studies. The fixed effects meta-analysis was properly used to calculate the pooled ORs and 95% CIs. Major findings: We eventually identified six studies evaluating the association of sarcoma risk with 309T>G polymorphism. People with 309-GG were found to have 43% greater risk of sarcoma relative to people with 309-TT (OR, 1.43; 95% CI, 1.01~2.03; Pheterogeneity, 0.45). In the G vs. T genetic model, the risk reduced to 19% (OR, 1.19; 95% CI, 1.01~1.40; Pheterogeneity, 0.50). Statistical data showed no significant heterogeneity or publication bias in the meta-analysis. Conclusion: These data demonstrate that 309T>G polymorphism located within the MDM2 gene may act as modifier factor for sarcomas. A weakness of this analysis is that the findings cannot be explainable when the subtypes are separated and additional larger investigations are needed to identify the role of 309T>G polymorphism in each form of sarcoma.