Published online Sep 14, 2013. doi: 10.3748/wjg.v19.i34.5693
Revised: March 25, 2013
Accepted: March 28, 2013
Published online: September 14, 2013
Processing time: 282 Days and 20.9 Hours
AIM: To evaluate the contribution of the G-197A polymorphism in the interleukin-17 (IL-17) promoter region to gastric cancer risk in an Iranian population.
METHODS: We performed a case control study using samples from 161 individuals with gastric cancer and 171 healthy controls. For each individual, the G-197A genotype was determined by restriction fragment length polymorphism analysis of polymerase chain reaction-amplified fragments. Statistical analyses were performed to determine whether any demographic or behavioral factors, infection with Helicobacter pylori (H. pylori), or a particular G-197A genotype was associated with gastric cancer risk.
RESULTS: We found that the G-197A genotype was significantly associated with increased gastric cancer risk (P = 0.001). Patients who were homozygous (AA) at position -197 were 2.9 times more likely to develop disease (95%CI: 1.56-5.4; P = 0.001). Furthermore, logistic regression analysis revealed that the presence of a single A allele increased the risk of gastric cancer up to 1.7-fold (95%CI: 1.26-2.369; P = 0.001). This association was observed for early stage gastric adenocarcinomas only, and was not linked to H. pylori infection.
CONCLUSION: These results suggest that carrying one or more G-197A polymorphisms at position -197 in the IL-17 promoter region significantly increases gastric cancer risk in this patient population.
Core tip: There is currently a need for genetic markers to identify individuals at risk for developing gastric cancer. In this study, we describe one such marker, a G-197A polymorphism in the interleukin-17A (IL-17A) promoter. Within our study population, individuals who carry the G-197A polymorphism in the IL-17A promoter region may be at a significantly greater risk of developing gastric cancer. Importantly, the presence of this polymorphism alone was sufficient to increase risk of gastric cancer development.