Purpose:
Circular RNAs (
circRNAs) as prognostic
biomarkers have spurred considerable interest in several types of
tumors. In the present study, we aimed to elucidate the clinicopathological and prognostic values of
circRNAs in human
cancer. Methods: We systematically searched PubMed Central (PMC), PubMed, Web of Science, EMBASE, Scopus, CBM and the Cochrane Library databases up to Nov 29, 2018. Eligible studies reporting on the association between
circRNAs expression and clinicopathological and prognostic outcomes in
cancer were incorporated. Pooled odds ratios (
ORs) and 95% confidence intervals (CIs) were used to assess clinicopathological parameters, and hazard ratios (HRs) and 95% CIs to estimate overall survival (OS). Results: Thirty-two studies involving 4529 patients were incorporated into our meta-analysis. Pooled results showed that high expression of oncogenic
circRNAs was significantly associated with poor clinicopathological characteristics (
tumor size: OR=1.29, 95%Cl: 1.10-1.51; TNM stage: OR=1.62, 95%Cl: 1.41-1.87; differentiation grade: OR=1.41, 95%Cl: 1.11-1.78;
lymph node metastasis: OR=1.69; 95%Cl: 1.34-2.13; distant
metastasis: OR=2.75; 95%Cl: 1.92-3.95) and a poor prognosis (OS: HR=2.75; 95%Cl: 2.34-3.15). Furthermore, we found that high expression of
tumor-suppressor
circRNAs was correlated with improved clinical characteristics (
tumor size: OR=0.72; 95%Cl: 0.56-0.92; TNM stage: OR=0.77, 95%Cl: 0.68-0.88) and longer survival times (OS: HR=0.49; 95%Cl: 0.42-0.56). Subgroup analyses based on
cancer types and
circRNA types were also performed. Conclusion: Our study indicates that
circRNAs may serve as important
biomarkers for clinicopathologic features and prognosis in human
cancer.