Abstract
This meta-analysis aimed to provide an up-to-date comprehensive evaluation on the association between the MDM2 40bp indel polymorphism and cancer susceptibility. Eligible studies were retrieved by searching Web of Science, PubMed, Scopus, and Google scholar databases up to August 27, 2018. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of association between the polymorphism and cancer risk. The findings of this meta-analysis revealed that the 40bp indel polymorphism significantly increased the risk of overall cancer risk in heterozygous (OR=1.06, 95%CI=1.01-1.11, P=0.016) and ID+DD (OR=1.07, 95%CI=1.01-1.14, P=0.027) genotypes. Stratified analysis by cancer type proposed that the study indel variant significantly associated with the risk of gastrointestinal cancer in heterozygous (OR=1.18, 95%CI=1.06-1.32, P=0.003) and ID+DD (OR=1.18, 95%CI=1.06-1.30, P=0.002) genotypes. The present findings showed a significant association between the MDM2 40bp indel polymorphism and overall cancer risk as well as gastrointestinal cancer susceptibility. Larger and well-designed researches are required to validate the findings association in detail.