Interleukin-17 gene polymorphisms contribute to cancer risk.

Epidemiological studies have suggested that interleukin-17 (IL-17) polymorphisms are associated with cancer risk. However, the results of these studies are inconsistent. Therefore, we performed a meta-analysis to obtain a precise conclusion. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association of the IL-17A rs2275913G>A and IL-17F rs763780T>C polymorphisms with cancer risk. Publication bias and sensitivity analyses were performed to ensure the statistical power. Overall, 10 relevant case-control studies involving 4,516 cases and 5,645 controls were included. The pooled ORs with 95% CIs indicated that the IL-17A rs2275913G>A polymorphism was significantly associated with increased cancer risk (for A versus G: OR = 1.28, 95% CI: 1.16-1.41, P < 0.001, I (2) = 61.1%; for GA versus GG: OR = 1.12, 95% CI: 1.02-1.23, P = 0.015, I (2) = 27.8%; for AA versus GG: OR = 1.71, 95% CI: 1.38-2.41, P < 0.001, I (2) = 69.6%; for GA + AA versus GG: OR = 1.23, 95% CI: 1.13-1.34, P < 0.001, I (2) = 6.4%; for AA versus GG + GA: OR = 1.62, 95% CI: 1.27-2.07, P < 0.001, I (2) = 81.4%). Succeeding analysis of HWE and stratified analysis of gastric cancer and the Asian (and Chinese) population revealed similar results. The IL-17F rs763780T>C polymorphism was also significantly associated with gastric cancer development. Overall, the present meta-analysis suggests that IL-17 polymorphisms increase the risk of developing cancer, particularly gastric cancer, in the Asian (and Chinese) population.