Dysregulation of circular RNAs (circRNAs) has been reported in many types of cancer. However, the clinico-pathological and prognostic values of circRNAs in digestive system cancers are still unclear. This meta-analysis was performed to investigate the potential prognostic role of circRNAs in digestive system malignancies. An electronic comprehensive literature search was conducted to determine eligible studies reporting the prognostic value circRNAs in digestive system malignancies. Pooled hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals (CIs) were extracted to evaluate the association between circRNAs and overall survival (OS) and clinico-pathological parameters. A total of 111 eligible studies were included in this meta-analysis. The results showed a significant association between high expression of oncogenic circRNAs and poor OS (HR=1.90; 95% CI, 1.67- 2.16; P<0.001). However, overexpression of tumor‐suppressor circRNAs had no significant correlation with patients’ OS (HR=0.78; 95% CI, 0.50- 1.07; P:0.088). Furthermore, upregulated circRNAs were correlated with increased tumor stage; OR=2.68; 95% CI, 2.09-3.45; P<0.001, tumor size; OR=1.52; 95 CI, 1.69-1.98; P<0.001. Also a significant invers correlation was found between downregulated circRNAs and advanced tumor stage; OR=0.44; 95% CI, 0.25-0.79; P<0.001, Tumor size; OR=0.51; 95 CI, 0.34-0.77; P=0.006. Our meta-results suggest that aberrant expression of circRNAs might be an indicative of poor prognosis and advanced disease in patients with digestive system malignancies. Further investigations are needed to determine the value of circRNAs levels in clinical management of patients.

Keywords: Circular RNA, digestive system cancer, meta-analysis, prognosis, biomarker

     

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