A shared susceptibility locus in p53 for both gastric cancer and esophageal cancer in a northwestern Chinese population

Abstract

Background Upper gastrointestinal cancers are the leading causes of cancer-related deaths in Northwest China and share many similarities in terms of histological type, risk factors and genetic variants. We hypothesized that shared common genetic SNPs among eight SNPs in the p53 pathway existed among Ningxia gastric cancer (GC) and esophageal cancer (EC) patients. Methods A total of 180 GC cases, 113 EC cases and 358 cancer-free control subjects from a high-incidence area for upper gastrointestinal cancers in Ningxia, China, were enrolled in this study. The genotyping of 8 SNPs was performed using PCR direct sequencing. P53 expression in GC and EC tissues was examined using the S-P immunohistochemical method. Multiple logistic regression analyses were used to estimate the association between genotypes and GC or EC risks. Kaplan-Meier and multivariate Cox regression analyses were carried out to evaluate the associations between genetic variants and overall survival. Result rs1042522 was a common genetic locus shared by both Ningxia GC and EC patients. Compared with the rs1042522 Pro allele, the rs1042522 Arg allele increased the GC risk by 1.810 times and the EC risk by 2.285 times. Additionally, patients who carried the rs1042522 Arg allele and who also smoked or consumed alcohol had an increased risk for GC and EC. Cox survival analysis showed that neither p53 nor rs1042522 had an effect on the prognosis of GC and EC patients. Conclusion rs1042522 was a common genetic locus responsible for susceptibility shared by both northwestern GC and EC Chinese patients. Tobacco smoking and alcohol drinking further enhanced the cancer risk in our study.