Goals: Investigated the association of DNA repair gene xeroderma pigmentosum group A(XPA) and C(XPC) polymorphisms with the risk of gastric cardiac adenocarcinoma (GCA) in a high incidence region in north China.
Background: Polymorphisms of a number of DNA repair genes may contribute to variations in DNA repair capacity and genetic susceptibility to different cancers.
Study: Two single nucleotide polymorphisms of XPA and 3 single nucleotide polymorphisms of XPC were genotyped in 253 GCA patients and 612 healthy controls.
Results: Family history of upper gastrointestinal cancer may increase the risk of developing GCA. Compared with A/A genotype, A/G+G/G genotype of XPA A23G significantly decreased the risk of developing GCA especially in nonsmoker group. The genotype and allelotype distributions of XPC intron 9 PAT+/- and exon 15 Lys939Gln in GCA patients were not significantly different from that in healthy controls (P>0.05). T allelotype frequencies of XPC exon 8 Val499Ala in GCA patients was significantly lower than that in healthy controls (P<0.05). The C/T genotype frequency of XPC exon 8 in GCA patients (35.6%) was significantly different from that in healthy controls (46.1%) (P=0.01). Compared with individuals with C/C genotype, individuals with T allele (C/T or T/T genotype) had significantly lower risk in developing GCA. We also found that polymorphisms of this 3 XPC locus were in linkage disequilibrium.
Conclusions: XPA A23G and XPC exon 8 Val499Ala polymorphisms may be useful markers for identifying individuals at risk of developing GCA in the high incidence region of north China.