The diagnostic value of circulating cell free DNA quantification in non-small cell lung cancer: A systematic review with meta-analysis

• CfDNA could differentiate primary lung cancer from healthy individuals with a high sensitivity and specificity.
• Sensitivity could not be improved according to the grouping factors.
• Specificity was near to 90% when we unified the sample condition, detection method and reference gene.
• Combination of cfDNA quantification with other tumor markers would be the future directions.

ObjectivesThe aim of the current study was to assess the diagnostic value of circulating cell free DNA (cfDNA) quantification in discriminating non-small cell lung cancer (NSCLC) from healthy individuals.Materials and methodsAn electronic search was conducted on PubMed, EMBASE, Web of Science, and Cochrane Library. Eligible studies regarding to examine the diagnostic value of cfDNA in the detection of NSCLC were extracted and analyzed.ResultsWe identified 15 eligible studies with a total of 2125 patients. The pooled results for quantification of cfDNA in lung cancer screening in the included studies were as follows: sensitivity, 81% (95% confidence interval (CI), 76%–84%); specificity, 85% (95% CI, 77%–91%); diagnostic odds ratio, 23.87 (95% CI, 13.37–42.61); and areas under the summary receiver operating characteristic curves were 0.89 (95% CI, 0.86–0.92). Subgroup analyses according to the time of sample collection, sample materials, test method, reference gene and cutoff value did not improve sensitivity, but specificity could be significantly improved when we only included the studies using cfDNA sample before surgery or antitumor treatment and real-time PCR to detect cfDNA and human β-actin as a reference gene.ConclusionQuantification of cfDNA was a promising and effective biomarker for discriminating NSCLC from healthy individuals.