Strong association between lung cancer and the AXIN2 polymorphism.

Accumulated evidence suggests that alterations due to mutations or genetic polymorphisms in the AXIN2 tumor suppressor gene, a component of the Wnt signaling pathway, contributes to carcinogenesis. The effect of the AXIN2 exon 1 148 C↷T polymorphism was recently investigated in a Japanese population, but has not been investigated in other populations. Additionally, other common polymorphisms of this gene have not been studied. In the present study, 8 polymorphisms of the AXIN2 gene, including exon 1 148 C↷T, were investigated in a Turkish population of 100 lung cancer patients using PCR-RFLP methods. For the exon 1 432 C↷T, exon 5 1365 G↷A, exon 5 1386 C↷T, intron 5 1712+19 G↷T, exon 7 2062 C↷T and intron 7 2141+73 G↷A single nucleotide polymorphisms of AXIN2, no significant association was found between the controls and the lung cancer patients. For exon 1 148 C↷T, a statistically significant association between the controls and lung cancer patients was found. For this region, lung cancer patients with the TT genotype showed a decreased risk [odds ratio (ORTT) 0.33, 95% confidence interval (CI) 0.12-0.89; p=0.032 (adjusted for age, gender and smoking status)] as compared with the controls with the CC genotype. Concerning histological tumor type, it has been found that exon 1 148 C↷T SNP is associated with a significant decreased risk in squamous cell carcinoma patients (ORTT 0.16; 95% CI 0.03-0.79; p=0.014). Male (ORTT 0.19; 95% CI 0.04-0.77; p=0.015) and smoker (ORTT 0.11; 95% CI 0.01-0.71; p=0.019) lung cancer patients with the TT genotype showed a decreased risk for the same region. Our results suggest that the risk of lung cancer in a Turkish population is related to polymorphisms of the AXIN2 gene.