Meta-analysis of Circulating Tumor Cells as a Prognostic Marker in Lung Cancer

Introduction: Recent studies have shown that circulating tumor cells (CTCs) play potential roles asdiagnostic and prognostic biomarkers with various cancer types. The aim of this study was to comprehensivelyand quantitatively summarize the evidence for the use of CTCs to predict the survival outcome of lung cancerpatients. Materials and
Methods: Relevant literature was identified using Medline and EMBASE. Patients’ clinicalcharacteristics, overall survival (OS) and progression-free survival (PFS) together with CTC positive rates atdifferent time points (before, during and after treatment) were extracted. A meta-analysis was performed toclarify the prognostic role of CTCs and the correlation between the CTC appearance and clinical characteristics.
Results: A total of 12 articles containing survival outcomes and clinical characteristics and 15 articles containingonly clinical characteristics were included for the global meta-analysis. The hazard ratio (HR) for OS predictedby pro-treatment CTCs was 2.61 [1.82, 3.74], while the HR for PFS was 2.37 [1.41, 3.99]. The HR for OSpredicted by post-treatment CTCs was 4.19 [2.92, 6.00], while the HR for PFS was 4.97 [3.05, 8.11]. Subgroupanalyses were conducted according to histological classification and detection method. Odds ratio (OR) showedthe appearance of pro-treatment CTCs correlated with the lymph node status, distant metastasis, and TNMstaging, while post-treatment CTCs correlated with TNM staging only.
Conclusion: Detection of CTCs in theperipheral blood indicates a poor prognosis in patients with lung cancer.