Diagnostic performance of circulating tumor cells in lung cancer: a systematic review and meta-analysis

Background: Previous studies have reported conflicting findings regarding the diagnostic value of circulating tumor cells (CTCs) for detecting lung cancer. In this study, we performed a meta-analysis to consolidate all the current evidence to assess the diagnostic value of CTCs in lung cancer. Materials & methods: We conducted a literature search of the PubMed, Embase, and Cochrane library databases from inception to June 2016 to identify relevant studies. The quality of the studies was assessed using the revised Quality Assessment for Studies of Diagnostic Accuracy tool. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristic (sROC) curve for CTC detection in individual studies were calculated and analyzed using a random effects model. Deek's funnel plots were used to evaluate publication bias. Results: Fifteen studies were included in the final meta-analysis. The pooled sensitivity of CTCs for lung cancer diagnosis was 0.63 (95% confidence interval [CI]: 0.60-0.65), and the pooled specificity was 0.94 (95% CI: 0.92-0.95). The pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 15.62 (95% CI: 5.8841.51), 0.39 (95% CI: 0.30-0.49), and 41.0 (95% CI: 16.6-101.3), respectively. The observed area under the sROC curve for CTCs and lung cancer was 0.9298. Conclusion: This systematic review suggests that CTCs detection alone cannot be recommended as a screening test for lung cancer. However, it might be used as a noninvasive method for the confirmation of the lung cancer diagnosis.