P53 codon 72 polymorphism and risk of gastric cancer in a Chinese population

The p53 gene plays an important role in cell cycle control in response to DNA damage, which may increase the probability of mutations that lead to carcinogenesis. The p53 codon 72 Arg↷Pro polymorphism has been suggested to be associated with risk for different kind of cancers, but the data on gastric cancer (GC) is very limited. To evaluate the association between this polymorphism and risk of GC, we performed genotype analysis by using a polymerase chain reaction-based restriction fragment length polymorphism assay in a population-based case-control study of 324 GC patients and 317 cancer-free controls in a Chinese population. The controls were frequency-matched to the cases by age, sex and smoking status. The frequency of the p53 Arg allele was 57.4% in the cases and 54.9% in the controls, and the genotype frequencies of p53 Arg/Arg, Arg/Pro, and Pro/Pro were 29.6%, 55.6%, and 14.8%, respectively, in the cases, and 29.6%, 50.5%, and 19.9%, respectively, in the controls (p=0.207). Logistic regression analysis revealed that the p53 Arg allele (Arg/Pro and Arg/Arg genotype) was associated with a borderline significantly increased risk of gastric cancer (adjusted OR=1.44, 95% CI=0.95-2.18), particularly non-cardia gastric cancer (adjusted OR=1.67, 95% CI=1.00-2.77), compared with p53 homozygous Pro allele (Pro/Pro genotype), and the risk was significantly more evident among alcohol drinkers (adjusted OR=2.85, 95% CI=1.37-5.95). While the results suggest that the p53 codon 72 polymorphism may contribute to gastric cancer susceptibility, further larger studies are needed to substantiate our findings and to explore a possible interaction between p53 codon 72 polymorphism and alcohol in the etiology of gastric cancer.