Association of TP53 gene codon 72 polymorphism with Helicobacter pylori-positive non-cardia gastric cancer in Vietnam.

INTRODUCTION: This research aimed to determine the association of the combination of H. pylori infection and TP53 codon 72 polymorphism with non-cardia gastric cancer (GC) in Vietnam.

METHODOLOGY: A total of 164 patients with non-cardia GC and 164 patients with peptic ulcer disease or functional dyspepsia in controls matched by sex and age were enrolled. H. pylori infection was diagnosed by rapid urease test and polymerase chain reaction (PCR). The cagA gene-positivity and vacA sm subtypes were determined by multiplex PCR. Genotypes of TP53 codon 72 polymorphism were determined by PCR-restriction fragment length polymorphism.

RESULTS: The prevalence of H. pylori infection in GC and control group were 61.6% and 55.4%, respectively. The rates of cagA-positive strains in the two H. pylori-positive groups were 80.2% and 71.4%, respectively. There was no statistically significant difference in TP53 codon 72 genotype distribution between GC group (frequencies of Arg/Arg, Arg/Pro and Pro/Pro genotypes were 31.1%, 43.3% and 25.6%, respectively) and controls (29.3%, 52.4% and 18.3%, respectively), p = 0.172. The significant difference in genotype distribution was observed in recessive model (Pro/Pro vs Arg/Arg + Arg/Pro) when stratifying by H. pylori infection (OR = 2.02, 95% CI 1.03-3.96, p = 0.041) and by cagA-positivity (OR = 2.33, 95% CI 1.07-5.07, p = 0.032).

CONCLUSIONS: This study suggests a synergistic interaction between H. pylori infection, especially cagA-positive H. pylori, and Pro/Pro genotype of TP53 codon 72 polymorphism might play a significant role in the pathogenesis of GC in the Vietnamese population.