LncRNAs act as prognostic biomarkers in gastric cancer: A systematic review and meta-analysis

Gastric cancer (GC) is one of the leading causes of cancer-related death. The 5-year overall survival (OS) rate of patients is extremely low and to find a new marker is urgently needed. Increasing studies indicate that long noncoding RNAs (lncRNAs) are abnormally expressed in GC. However, the results of these studies were conflicting and inconclusive, especially in the aspects of tumor prognosis. Therefore, we performed a systematic review and meta-analysis to investigate the clinical values, including prognosis and clinicopathology of different lncRNAs in GC. A total of 38 studies including 34 on OS, 17 on disease-free survival (DFS), 1 on progression-free survival (PFS), 1 on disease-specific survival (DSS), and 34 on clinicopathological features were identified from the databases. Our results indicated that the levels of lncRNAs were associated with the OS (hazard ratios [HR] = 1.44, 95% confidence interval [95% CI] = 1.23-1.69, P < 0.001), PFS (HR = 2.32, 95% CI = 1.10-5.28, P = 0.001) and DSS (HR = 2.65, 95% CI = 1.53-3.60, P = 0.009). However, there was no relationship between lncRNAs and DFS (HR = 1.25, 95% CI = 0.90-1.74, P = 0.11). Moreover, lncRNAs were related to lymph node metastasis (odds ratios [OR] = 1.67, 95% CI = 1.21-2.31, P = 0.002) and TNM (OR = 1.93, 95% CI = 1.27-2.92, P < 0.001). In conclusion, our present meta-analysis indicated that lncRNAs could function as potential prognostic markers in GC.