P53 codon 72 polymorphism and colorectal cancer: a meta-analysis of epidemiological studies.

Background/Aims: Studies investigating the association between p53 codon 72 polymorphism and colorectal cancer risk report conflicting results. In order to clarify this, we carried out a meta-analysis using published data to obtain more precise estimates of risk. Methodology: Electronic searches of PubMed and EMBASE were conducted to select studies for this meta-analysis. The principal outcome measure was the odds ratio (OR) with 95% confidence interval (CI) for the risk of colorectal cancer associated with p53 codon 72 genotype. Results: We identified seven epidemiological studies, which included 1964 colorectal cancer cases and 2943 controls. The combined results based on all studies showed that there was no significant difference in genotype distribution [Arg/Arg (OR=0.86, 95% CI=0.68, 1.08); Pro/Pro (OR=1.27, 95% CI=0.96, 1.68); Pro/Arg (OR=1.04, 95% CI=0.92, 1.17)] between colorectal cancer and non-cancer patients. When stratifying for race, we found that patients with colorectal cancer had a significantly higher frequency of Pro/Pro (OR=1.79, 95% CI=1.37, 2.35) and lower frequency of Arg/Arg (OR=0.66, 95% CI=0.44, 0.98) than controls among Asians. No statistical association was found between this genotype and alcohol, tobacco, stage, histological differentiation, lymph node metastasis of colorectal cancer. Conclusions: Our meta-analysis suggests that the p53 codon 72 polymorphism may be associated with colorectal cancer among Asians.