Clinical significance of plasma free DNA in patients with non-small cell lung cancer

Objectives Plasma free DNA is a promising new tumor biomarker, which may have applications in clinical diagnosis and treatment of non-small cell lung cancer (NSCLC). Methods Plasma free DNA was collected from 120 healthy controls and 116 patients with NSCLC before and after treatment. Results The mean plasma free DNA levels in 116 NSCLC patients (200.70 ± 88.54 ng/mL) were higher than those of 120 healthy controls (18.65 ± 6.30 ng/mL). Further analysis showed that the mean serum free DNA level in stage I/II NSCLC patients was 172.75 ± 72.87 ng/mL, significantly lower than that of stage III/IV patients (221.88 ± 93.86 ng/mL). Following surgery and effective chemotherapy, the plasma free DNA levels of NSCLC patients decreased significantly. Conclusions Through quantitation of plasma free DNA, this study established proof-of-concept for a highly sensitive and specific detection method, which can be used for diagnosis, prognosis and treatment monitoring in NSCLC patients