Background: Variants in the axis inhibition 2 (AXIN2) gene might alter the protein's structure or function or create a multiprotein destruction complex in the Wnt signaling pathway and thus affect an individual's susceptibility to cancer. The objective of this study is to evaluate broadly the evidence available for the AXIN2 rs2240308 polymorphism and risk of cancer.
Methods: A comprehensive literature search was undertaken for eligible studies in Embase, PubMed, and Cochrane Library up to Nov 30, 2014. Odds ratios (ORs) and the corresponding 95 % confidence intervals (CIs) were used to measure the strength of the models.
Results: Eight articles (10 case-control studies with 1,502 cases and 1,590 controls) were included in this analysis. Overall, the AXIN2 rs2240308 polymorphism was associated with a significant increase in the risk of cancer (G allele vs. A allele: OR = 1.21, 95 % CI = 1.05-1.40, I (2) = 39.5 % and P Q = 0.094 for heterogeneity; GG vs. AA: OR = 1.30, 95 % CI = 1.04-1.63, I (2) = 35.9 % and P Q = 0.121 for heterogeneity; GG vs. GA + AA: OR = 1.36, 95 % CI = 1.17-1.58, I (2) = 19.5 % and P Q = 0.263 for heterogeneity). Asian populations showed similar results. Stratified analysis by cancer types indicated that the AXIN2 rs2240308 polymorphism increases the risk of lung cancer (G allele vs. A allele: OR = 1.36, 95 % CI = 1.17-1.59; GA vs. AA: OR = 1.43, 95 % CI = 1.01-2.02; GG vs. AA: OR = 1.93, 95 % CI = 1.36-2.75; GG + GA vs. AA: OR = 1.65, 95 % CI = 1.18-2.30; GG vs. GA + AA: OR = 1.45, 95 % CI = 1.18-1.79. All I (2) < 50 % and P Q > 0.100 for heterogeneity).
Conclusions: This study showed that the AXIN2 rs2240308 polymorphism contribute to increasing the risk of cancer, especially lung cancer in Asian populations.
Keywords: AXIN2; Cancer; Meta-analysis; Polymorphism; Risk.