Role of p53 codon 72 polymorphism in the risk of development of distal gastric cancer.

Objective: Mutations in the codon 72 of exon 4 in the p53 gene have been associated with higher risk in the development of several types of cancer. This polymorphism occurs with two alleles encoding either arginine (CGC) or proline (CCC). The aim of this study was to assess the role of the codon 72 polymorphism of p53 in the risk for the development of distal gastric cancer (GC) in a Mexican population.

Material And Methods: We studied 247 patients who were enrolled at the Servicio de Gastroenterologia, Hospital Universitario "Dr. José Eleuterio González" Universidad Autónoma de Nuevo León. The study group included 65 distal GC cases [mean age, 58.2 (22-84), median = 60, F:M = 0.6] and 182 patients without evidence of GC [mean age 53.9 (18-89), median = 53, F:M = 1.07) as the control group. The polymorphism in the codon 72 of the p53 gene was determined by PCR-RFLP in all the patients.

Results: As expected, the majority of GC patients were old male. We found a previously unknown association of the Arg/Arg genotype and distal GC (OR: 1.96, 95% confidence interval [CI] = 1.06-3.61, p =0.03). Because of age and gender differences, cases and controls were matched in those two variables and the association of Arg/Arg genotype with distal GC persisted (OR: 2.29, 95% CI = 1.22-4.32, p = 0.01). When cases and controls were matched by age, gender, H. pylori positivity and excluding patients with atrophic gastritis and/or intestinal metaplasia (n=97) the association was stronger (OR = 2.37, 95% CI = 1.18-4.77, p = 0.01).

Conclusions: The results of this study suggest that the carriage of the Arg/Arg genotype could be associated with the development of distal GC in this Mexican population.