title: Circulating Cell Free DNA as the Diagnostic Marker for Ovarian Cancer: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Quantitative analyses of circulating cell-free DNA (cfDNA) are potential methods for the detection of ovarian cancer. Many studies have evaluated these approaches, but the results were too inconsistent to be conclusive. This study is the first to systematically evaluate the accuracy of circulating cfDNA for the diagnosis of ovarian cancer by conducting meta-analysis.
  
  
  METHODS
  We searched PubMed, Embase, Cochrane Library and the Chinese National Knowledge Infrastructure (CNKI) databases systematically for relevant literatures up to December 10, 2015. All analyses were conducted using Meta-DiSc1.4 and Stata 12.0 software. Sensitivity, specificity and other measures of accuracy of circulating cfDNA for the diagnosis of ovarian cancer were pooled. Meta-regression was performed to identify the sources of heterogeneity.
  
  
  RESULTS
  This meta-analysis included a total of 9 studies, including 462 ovarian cancer patients and 407 controls. The summary estimates for quantitative analysis of circulating cfDNA in ovarian cancer screen were as follows: sensitivity, 0.70 (95% confidence interval (CI), 0.65-0.74); specificity, 0.90 (95% CI, 0.87-0.93); positive likelihood ratio, 6.60 (95% CI, 3.90-11.17); negative likelihood ratio, 0.34 (95% CI, 0.25-0.47); diagnostic odds ratio, 26.05 (95% CI, 14.67-46.26); and area under the curve, 0.89 (95% CI, 0.83-0.95), respectively. There was no statistical significance for the evaluation of publication bias.
  
  
  CONCLUSIONS
  Current evidence suggests that quantitative analysis of cfDNA has unsatisfactory sensitivity but acceptable specificity for the diagnosis of ovarian cancer. Further large-scale prospective studies are required to validate the potential applicability of using circulating cfDNA alone or in combination with conventional markers as diagnostic biomarker for ovarian cancer and explore potential factors that may influence the accuracy of ovarian cancer diagnosis.
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Bingjie
authors.initials: B
authors.lastname: Leng
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Wenfei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Ze
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Manzhen
authors.initials: M
authors.lastname: Zuo
authors.affiliation: Department of Gynecology and Obstetrics, the People's Hospital of Three Gorges University/the First People's Hospital of Yichang, Yichang 443000, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Chen
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D004273:DNA, Neoplasm / Q000097:blood*; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000097:blood* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm