The Impact of MicroRNA-133a on Prognosis and Clinicopathological Parameters for Digestive System Cancers: a Comprehensive Study Based on Meta-Analysis and TCGA Database

We conducted a meta-analysis on the impact of microRNA-133a (miR-133a) on digestive system cancers, and verified the results through The Cancer Genome Atlas (TCGA). Relevant studies were searched in English and Chinese database and meta-analysis was performed using Stata 12.0. The corresponding information of miR-133a and digestive system cancers were obtained from TCGA database and analysis was performed using SPSS. Increased miR-133a expression was linked with favorable overall survival (OS) in digestive system cancers (HR = 0.539, 95% CI: 0.416-0.698, P < 0.001), digestive tract cancers (HR =0.558, 95% CI: 0.406-0.767, P < 0.001), esophageal squamous cell carcinoma (ESCC) (HR = 0.427, 95% CI: 0.265-0.690, P = 0.001) and gastric cancer (HR = 0.541, 95% CI: 0.385-0.761, P < 0.001). The expression of miR-133a was significantly lower in cancer tissue compared with adjacent tissue for ESCC (P < 0.001), gastric cancer (P < 0.001), colorectal cancer (P < 0.001) and hepatocellular carcinoma (P = 0.002). Meanwhile, the area under the ROC curve (AUC) value for miR-133a was 0.836, 0.888, and 0.99 in ESCC, gastric cancer and colorectal cancer. MiR-133a is a tumor suppressor with prognostic and diagnostic values for digestive system cancers. High miR-133a expression was associated with better prognosis and less adverse clinicopathological parameters. More research should be performed to test these findings.