Wnt signaling pathway pharmacogenetics in non-small cell lung cancer

Wingless-type protein (Wnt)/β-catenin pathway alterations in non-small cell lung cancer (NSCLC) are associated with poor prognosis and resistance. In 598 stage III-IV NSCLC patients receiving platinum-based chemotherapy at the MD Anderson Cancer Center (MDACC), we correlated survival with 441 host single-nucleotide polymorphisms (SNPs) in 50 Wnt pathway genes. We then assessed the most significant SNPs in 240 Mayo Clinic patients receiving platinum-based chemotherapy for advanced NSCLC, 127 MDACC patients receiving platinum-based adjuvant chemotherapy and 340 early stage MDACC patients undergoing surgery alone (cohorts 2-4). In multivariate analysis, survival correlates with SNPs for AXIN2 (rs11868547 and rs4541111, of which rs11868547 was assessed in cohorts 2-4), Wnt-5B (rs12819505), CXXC4 (rs4413407) and WIF-1 (rs10878232). Median survival was 19.7, 15.6 and 10.7 months for patients with 1, 2 and 3-5 unfavorable genotypes, respectively (P=3.8 × 10^-9). Survival tree analysis classified patients into two groups (median survival time 11.3 vs 17.3 months, P=4.7 × 10^-8). None of the SNPs achieved significance in cohorts 2-4; however, there was a trend in the same direction as cohort 1 for 3 of the SNPs. Using online databases, we found rs10878232 displayed expression quantitative trait loci correlation with the expression of LEMD3, a neighboring gene previously associated with NSCLC survival. In conclusion, results from cohort 1 provide further evidence for an important role for Wnt in NSCLC. Investigation of Wnt inhibitors in advanced NSCLC would be reasonable. Lack of an SNP association with outcome in cohorts 2-4 could be due to low statistical power, impact of patient heterogeneity or false-positive observations in cohort 1.