Objective: A functional single nucleotide polymorphism (SNP) at codon 72 of the gene for p53 protein (p53 R72P) has been implicated in a variety of human cancers, but the relationship between this SNP and hepatocellular carcinoma (HCC) remains obscure despite the fact that the critical role of p53 protein in HCC has been documented. This study was conducted to evaluate the link between the polymorphism with HCC stratified by chronic hepatitis B infection status in a Chinese population.
Methods: Four hundred and sixty-nine HCC cases (359 HbsAg-positive, 110 HbsAg-negative) and 567 controls (137 HbsAg-positive, 430 HbsAg-negative) were studied. The p53 genotypes were determined by a PCR based restriction fragment length polymorphism (RFLP) method.
Results: Overall, no correlation between HCC and the R72P genotypes was found when comparing all cases to controls or when comparing the HbsAg-positive HCC subgroup to controls. However, in HbsAg-negative subjects, the 72P allele was significantly associated with the presence of HCC (P=0.01) and had a higher risk (OR=1.69, 95% CI: 1.25-2.27) of HCC as compared to the 72R allele. By comparison to R/R homozygotes, the R/P heterozygotes and P/P homozygotes had a 1.73-fold (95% CI: 0.96-3.11) and a 3.29-fold (95% CI: 1.58-6.86) increased risk for HCC, respectively. The subjects with the 72P allele and a family history of HCC and those with the 72P allele and male gender also yielded an 11.14-fold (95% CI: 1.62-76.67) and a 9.39 fold (95% CI: 3.08-28.62) increased risk of HCC, respectively.
Conclusion: The P allele of the p53 R72P polymorphism has an increased risk for HCC in HbsAg-negative subjects, and exerts a synergistic influence on the risk for HCC when combined with HCC family history and the male gender.