Long noncoding RNA CCAT2 could serve as a novel prognostic biomarker in gastrointestinal cancers

Background: Numerous studies have shown that CCAT2, a newly discovered lncRNA, was aberrantly up-regulated in gastrointestinal cancers. Its over-expression correlated with clinical progression and poor prognosis. However, the clinical application of CCAT2 in gastrointestinal cancer remains unclear. Materials and methods: A systematic search was performed in PubMed, Web of Science, Cochrane Library together with Chinese National Knowledge Infrastructure (CNKI) and Wanfang database, the retrieval time was up to March 1, 2017. We identified relevant publications that focused on the prognostic and clinicopathological significance of CCAT2 in gastrointestinal cancers. Results: We included eight studies comprising 1039 patients in this meta-analysis. We found a significant association between upregulation of CCAT2 expression and poor overall survival (OS) (HR=1.51, 95% CI=1.281.75, p<0.001) in gastrointestinal cancers, and shorter disease-free survival (DFS) (HR=1.83; 95% CI=1.37-2.29; p<0.001) in gastric cancer. For OS, subgroup analyses were also performed to confirm the prognostic significance of CCAT2. Upregulation of CCAT2 correlated with unfavorable features such as tumor size, depth of invasion, lymph node metastasis and TNM stage in gastrointestinal cancers. Conclusions: CCAT2 might serve as a promising tumor-marker for predicting poor prognosis and adverse clinicopathologic characteristics in gastrointestinal cancers.