Long non-coding RNA-LET can indicate metastasis and a poor prognosis: a meta-analysis.

Recent studies have reported that long non-coding RNA low expression in tumor (lncRNA-LET) was down-regulated in several cancers. The current meta-analysis aims to determine whether lncRNA-LET can be used as a potential biomarker for metastasis and prognosis.We collected all relevant papers by searching multiple electronic databases (PubMed, EMBASE, Google Scholar, CNKI, Wanfang Database) and explored the association between the expression levels of lncRNA-LET and lymph node metastasis (LNM), distant metastasis (DM) and overall survival (OS).A total of 383 patients from four studies were finally included. The meta-analysis results showed that LNM occurred more frequently in patients from the lncRNA-LET low expression group than in patients from the lncRNA-LET overexpression group (OR=4.56, 95% CI 2.92-7.12, P<0.00001), and a similar result was observed between lncRNA-LET expression and DM (OR=4.77, 95% CI 2.29-9.94, P<0.0001). Additionally, we found that patients with low expression of lncRNA-LET had a poorer OS than those with lncRNA-LET overexpression (HR=2.39, 95% CI 1.57-3.21, P=0.000).lncRNA-LET may serve as a common molecular marker for metastasis and prognosis in human cancers.