Plasma cell-free DNA and survival in non-small-cell lung cancer: A meta-analysis

In recent years, plasma cell-free DNA (cfDNA) has been attracting increasing attention as a potential tumor marker, as this method is easily applied and minimally invasive. A series of studies have confirmed the association between the level of cfDNA and overall survival (OS) in non-small-cell lung cancer (NSCLC), but the findings remain inconclusive. We herein conducted a meta-analysis of published articles evaluating the correlation between the level of cfDNA and OS. A total of 9 studies enrolling 1,170 patients were included. For the overall population, a high level of cfDNA was found to be significantly correlated with worse OS [hazard ratio (HR) = 1.57, 95% confidence interval (CI): 1.18-2.10] in NSCLC. The subgroup analysis suggested that a high cfDNA level was associated with worse outcome in stage III-IV patients (HR=1.53, 95% CI: 1.07-2.19). However, the level of cfDNA and OS were not found to be significantly associated in the subgroup of patients with tumor stage I-II. The present meta-analysis revealed that a high level of cfDNA may be correlated with poor OS in NSCLC.