Abnormally expressed lncRNAs in the prognosis and clinicopathology of oesophageal cancer: a systematic review and meta-analysis

The relationship between the long noncoding RNA (lncRNA) expression and oesophageal cancer prognosis has been widely studied, but less consensus has been reached. We conducted this study to evaluate the relationship between the expression of lncRNAs and the prognosis and clinical pathology of oesophageal cancer. We conducted a systematic search of PubMed, EMBASE and Cochrane Library until 25 January 2019. Studies that evaluated the associations of a specific lncRNA with survival and/or clinicopathology of oesophageal cancer were included. Pooled hazard ratios (HRs), odds ratios (ORs), and corresponding 95% confidence intervals (CIs) were calculated using fixed or random-effect models. Sensitivity analysis was used to verify the stability of results. Publication bias was detected using Begg tests and adjusted utilizing the trim-and-fill method if a bias existed. A total of 51 studies comprising 6510 patients and regarding 41 lncRNAs were included in the present systematic review and meta-analysis. The results showed that dysregulation of lncRNAs was associated with overall survival, disease-free survival, and progression-free survival. The expression of lncRNAs was related to some certain clinicopathological parameters of oesophageal cancer, including tumour size, T classification, lymph node metastasis, tumour node metastasis (TNM) stage and differentiation. Among these findings, lncRNA AK001796, CASC9, HOTAIR, MALAT1 and UCA1 were identified and were expected to be ideal biomarkers for the prognosis and clinicopathology of oesophageal cancer. Although significant publication bias was observed in some studies, the results were not changed after adjustment using the trim-and-fill method. Abnormal lncRNA-expression profiles could serve as a promising indicator for prognostic evaluation of patients with oesophageal cancer. The combination of these lncRNAs will contribute to clinical decision-making in the future.