Prognostic value of wingless-type proteins in non-small cell lung cancer patients: a meta-analysis

Background: Wingless-type protein (Wnt) signaling pathway plays a crucial role in the development of human malignancies, such as epithelial-to-mesenchymal transition (EMT) and the maintenance of cancer stem cells (CSCs). Several studies have shown that the expression levels of Wnt proteins, ligands of Wnt signaling pathway, are related to clinical outcomes of non-small cell lung cancer (NSCLC) patients. This meta-analysis aimed to assess the prognostic value of Wnts proteins in patients with NSCLC. Methods: A multiple electronic literature search was conducted to identify all articles referring to the prognostic value of Wnt proteins in patients of NSCLC up to July 2016. Eligible studies were included in a meta-analysis in order to summarize the extracted data in terms of pooled hazard ratios (HRs) and their 95% confidence intervals (95% CIs). Results: Ten studies published between 2005 and 2015 were eligible for this meta-analysis. The total number of patients included was 1,805. The combined HR for all eligible studies evaluating the overall survival (OS) of NSCLC patients with positive Wnt expression was 1.60 (95% CI: 1.39-1.84). The subgroup analysis showed both Wnt1 and Wnt5a are associated with clinical outcome of NSCLC patients. Conclusions: Overexpression of Wnt proteins, as well as Wnt1 or Wnt5a alone, was markedly associated with adverse OS in lung cancer patients, suggesting that Wnts may act as a prognostic marker among NSCLCs.