Aim: To analyze the association between the p73 G4C14-to-A4T14 polymorphism (a.k.a., the GC/AT variation) and colorectal cancer risk and survival in the Korean population, and to evaluate the relationships between p73 polymorphism and the p73 protein expression or clinicopathological characteristics of colorectal cancer.
Methods: Three hundred and eighty-three histologically confirmed cases and 469 healthy controls, recruited at one teaching hospital in Pusan, Korea from 2001 and 2007, were genotyped for p73 G4C14-to-A4T14 by PCR with confronting two-pair primers (PCR-CTPP) and the expression profile of p73 in cancer tissues (n = 383) was analyzed by immunohistochemistry.
Results: Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression model adjusted for age and gender. Compared with the GC/GC genotypes, the GC/AT and AT/AT genotypes were significantly associated with colorectal cancer risk (GC/AT vs GC/GC: OR = 1.46, 95% CI: 1.10-1.94; AT/AT vs GC/GC: 1.72, 0.98-3.03; P(trend) = 0.01). When stratified by age and gender, the association was restricted to those less than 60 years of age (GC/AT or AT/AT vs GC/GC: 2.22, 1.39-3.55) and male (GC/AT or AT/AT vs GC/GC: 1.91, 1.31-2.77). The expression of p73 was associated with invasion depth (P = 0.003) and advanced Duke's stage (P = 0.06) of colorectal cancer. The patients with the GC/GC genotype were associated with worse survival compared with those with the other genotypes (P = 0.02). However, no significant relationship was observed between the p73 G4C14-to-A4T14 polymorphism and p73 protein expression in cancer tissues.
Conclusion: Our results suggest that the p73 GC/AT polymorphism is associated with an increased colorectal cancer risk and survival in the Korean population.