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.