Diagnostic and prognostic value of micro RNA-21 in colorectal cancer: An original study and individual participant data meta-analysis
Abstract
Background: We aimed to systematically summarize the diagnostic and prognostic value of circulating/tissue miR-21 in colorectal cancer (CRC) patients. Methods: An original study was conducted to explore the potential value of circulating miR-21 in CRC diagnosis and tissue miR-21 in CRC prognosis.
PUBMED and EMBASE were searched (to August, 2013) to identify eligible studies. In order to explore the diagnostic performance of circulating miR-21, meta-analysis methods were used to pool sensitivity, specificity, positive and negative likelihood ratio, diagnostic odd ratio and to construct a summary receiver-operating characteristic (ROC) curve.
For prognostic meta-analysis, study-specific hazard ratios (HRs) of tissue miR-21 for survival were summarized. Subgroup and sensitivity analyses were applied to explore heterogeneity.
Results: Finally 14 studies (including our study) were included in the meta-analyses. The pooled sensitivity, specificity and AUC of circulating miR-21 were 0.76 (95% CI 0.59-0.88), 0.81 (95% CI 0.76-0.85) and 0.81 (95% CI 0.78-0.85) in diagnosing CRC.
Patients with higher expression of tissue miR-21 had significant inferior overall survival (OS) (pooled HR=1.56, 95% CI 1.16-2.11) and disease-free survival (DFS) (pooled HR=1.35, 95% CI 1.08-1.69). The individual participant data (IPD) meta-analysis demonstrated that tissue miR-21 level was independently associated with worse CRC OS (HR=1.69, 95% CI 1.07-2.67; p=0.023), while this association seems to be confined to males (p=0.007) but not for females (p=0.845).
Conclusions: Circulating miR-21 level has potential value for CRC early detection, while high tissue miR-21 level is associated with adverse CRC prognosis. Impact: MiR-21 is a promising biomarker for early detection and prognosis of CRC.