Background & objective: p73 is a tumor suppressor gene. The two polymorphisms in the non-coding region of the exon 2 of p73 gene, named G4C14-A4T14, can form a stem-loop structure, and may influence p73 expression. This study was to investigate the correlation of p73 G4C14-A4T14 polymorphisms to susceptibilities to esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA) in a high incidence region of Hebei Province.
Methods: We conducted a population-based case-control study in 348 ESCC patients, 259 GCA patients, and 630 healthy controls. p73 genotypes were determined by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP).
Results: Family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing ESCC and GCA [the age, sex, and smoking status adjusted odds ratio (OR)=1.68, 95% confidence interval (CI)=1.28-2.20; OR=1.68, 95% CI=1.24-2.26, respectively]. The overall distribution of p73 genotype and allelotype in cancer patients and controls were not significantly different. Stratification analysis by smoking status and family history of UGIC found that the GC/AT genotype significantly increased the risk of developing GCA among the subjects without family history of UGIC (OR=1.71, 95% CI=1.14-2.57), while p73 G4C14-A4T14 polymorphisms did not increase the risk of developing ESCC and GCA in other subgroups.
Conclusion: In p73 G4C14-A4T14 polymorphisms, the GC/AT genotype increases the risk of developing GCA among the subjects without family history of UGIC.