Aim: To investigate the possible association of G-A single nucleotide polymorphism (SNP) at the -1082 position of interleukin (IL)-10 promoter with susceptibility to esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA) in a population of a high incidence region of North China.
Methods: IL-10-G1082A promoter SNP was genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) in 355 cancer patients (203 ESCC and 152 GCA) and 443 healthy controls.
Results: Smoking significantly increased the risk of ESCC and GCA development (the age and sex adjusted OR = 1.42 and 2.64, 95%CI = 1.11-1.81 and 1.46-4.76, respectively). Similarly, family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing ESCC and GCA (the age and sex adjusted OR = 1.44 and 3.10, 95%CI = 1.18-1.75 and 1.94-4.97, respectively). The A/A, A/G and G/G genotype frequencies of IL-10-G1082A were 60.3%, 37.0% and 2.7% in healthy controls, 57.6%, 39.9% and 2.5% in ESCC and 61.2%, 36.8% and 2.0% in GCA patients, respectively. The frequencies of A and G alleles were 78.8% and 21.2% in healthy controls, 77.6% and 22.4% in ESCC patients and 79.6%, 20.4% in GCA patients. The distribution of genotype and allelotype in ESCC and GCA patients was not significantly different from that in healthy controls (P>0.05). Compared to the A/A genotype, the combination of A/G and G/G genotypes did not show a significant effect on the risk of developing ESCC and GCA; the adjusted odds ratio was 0.92 (95% CI = 0.76-1.11) in ESCC and 0.95 (95% CI = 0.61-1.46) in GCA, respectively. When stratified for smoking status and family history of UGIC, the combination of A/G and G/G genotypes also did not show any significant influence on the risk of ESCC and GCA development compared to A/A genotypes.
Conclusion: IL-10-G1082A polymorphism might not be used as a stratification marker to predicate the risk of ESCC and GCA development in North China.