p73 G4C14 to A4T14 polymorphism is associated with colorectal cancer risk and survival

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.

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.

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.

Our results suggest that the p73 GC/AT polymorphism is associated with an increased colorectal cancer risk and survival in the Korean population.