Prognostic value of cyclin E expression in patients with ovarian cancer: a Meta-analysis.

PURPOSE Cell cycle is mainly mediated by cyclins, cyclin- dependent kinases (CDK), and CDK inhibitors. Cyclin E is the main regulator for transition from G1 to S phase, and is involved in cancer pathogenesis, progression and metastasis. Nevertheless, there is still a controversy of the prognostic value of cyclin E overexpression in ovarian cancer patients. This meta-analysis is the first study aimed at analyzing the effect of cyclin E overexpression on the prognosis of ovarian cancer. METHODS By systematically searching the PUBMED, EMBASE and MEDLINE databases for relevant articles with publication dates up to January 2016 and selection following inclusion and exclusion criteria, 8 studies with 1470 patients were enrolled in our meta-analysis. The overall survival (OS) of patients with cyclin E overexpression was calculated using hazard ratio (HR) with 95% confidence intervals (CIs). The studies were categorized according to the author and year, demographic data in each study, ovarian cancer related information, and cyclin E cut-off value. RESULTS Cyclin E overexpression in ovarian cancer was a poor prognostic factor with statistical significance for OS (HR=1.48, 95%CI: 1.12,1.85). Using confunnel, we found no publication bias in our analysis. CONCLUSION Cyclin E might be considered as a prognostic factor for ovarian cancer, as supported by our meta-analysis. However, more high-quality studies should be conducted to find better clinical use of cyclin E in ovarian cancer.