microRNA-21 (miR-21) is a small noncoding RNA that regulates gene expression in different types of human malignancies. The potential prognostic value of miR-21 in cancer progression is controversial. This meta-analysis includes 76 studies of 10,213 cancer patients to test miR-21 prognostic value in various human cancers. We obtain hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for overall survival (OS) to assess association strength. In the pooled analysis, high miR-21 expression is associated with poor OS, with a combined HR of 1.59 (95% CI, 1.49−1.70; p < 0.001; random-effects model). Furthermore, subgroup analysis demonstrates that high miR-21 expression is related to shorter OS in patients with digestive system cancers (HR = 1.02; 95% CI, 1.002 to 1.04; p = 0.026), respiratory system cancers (HR = 1.93; 95% CI, 1.48 to 2.51; p < 0.001), and breast cancer (HR = 2.20; 95% CI, 1.78 to 2.73; p = 0.001). These results indicate that miR-21 may be a clinically useful prognostic biomarker for cancer progression.

中文翻译：

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小非编码microRNA-21表达在癌症患者生存中的预后价值：荟萃分析。

microRNA-21（miR-21）是一种小的非编码RNA，可调节不同类型的人类恶性肿瘤中的基因表达。miR-21在癌症进展中的潜在预后价值存在争议。这项荟萃分析包括对10,213位癌症患者的76项研究，以测试miR-21在各种人类癌症中的预后价值。我们获得整体生存率（OS）的危险比（HRs）和相应的95％置信区间（CIs）以评估关联强度。在汇总分析中，高miR-21表达与不良OS相关，合并HR为1.59（95％CI，1.47-1.70；p <0.001；随机效应模型）。此外，亚组分析表明，miR-21的高表达与消化系统癌症患者的OS短相关（HR = 1.02； 95％CI，1.002至1.04；p= 0.026），呼吸系统癌症（HR = 1.93; 95％CI，1.48至2.51; p <0.001）和乳腺癌（HR = 2.20; 95％CI，1.78至2.73; p = 0.001）。这些结果表明，miR-21可能是癌症进展的临床有用的预后生物标志物。