IL-17A G197A and IL-17F T7488C polymorphisms and cancer risk in Asian populations: a meta-analysis.

PURPOSE

The association between Interleukin-17A (IL- 17A) G197A and IL-17F T7488C polymorphisms and risk for specific forms of cancer is inconclusive. We conducted a meta-analysis of all published studies to estimate the association of IL-17A G197A and IL-17F T7488C polymorphisms and cancer risk.

METHODS

A systematic computerized searching of the PubMed and Web of Science databases was performed for relevant publications. Data were extracted and statistical analysis was performed using RevMan 5.2 software.

RESULTS

Eight eligible case-control studies with 3,323 cases and 3,974 controls were included into this meta-analysis. The pooled odds ratios (ORs) showed that the IL-17A G197A polymorphism increased the risk for specific forms of cancer under the following genetic models: A vs G (OR = 1.31, 95 % CI 1.13-1.52, Ph - 0.02); AA vs GG (OR = 1.81, 95 % CI 1.30- 2.52, Ph = 0.007); AA /AG vs GG (OR = 1.26, 95 % CI 1.11- 1.43, Ph = 0.79); AA vs AG / GG (OR = 1.72, 95 % CI 1.16-2.53, Ph <0.0001). However, the IL-17F T7488C polymorphism did not increase or decrease cancer risk under all genetic models. Stratified analysis by cancer type revealed that the IL-17A G197A polymorphism may increase the risk of gastric cancer. Further subgroup analysis by country indicated that there was a statistically increased cancer risk in China.

CONCLUSIONS

The present meta-analysis showed the IL- 17A G197A polymorphism is associated with a significantly increased risk for specific forms of cancer, especially in gastric cancer. Subsequent studies with large sample size are warranted to validate this association.