Abstract
OBJECTIVE: To investigate the clinical value of plasma cell-free DNA (cfDNA) as a potential biomarker for advanced gastric cancer (GC). PATIENTS AND METHODS: One hundred and six cases of advanced gastric cancer patients receiving chemotherapy were selected as study objects. Another 40 healthy volunteers were included as control groups. Plasma cfDNA concentration was detected by (SuperbDNA(TM)) hybridization. Changes in cfDNA concentration during chemotherapy in patients with gastric cancer whose efficacy was assessed as partial response (PR), stable disease (SD) and disease progression (PD) were analyzed respectively. The relationship between the level of cfDNA and the efficacy of chemotherapy and clinical characteristics was also explored. In addition, cfDNA and other tumor markers were subjected to specificity and sensitivity analyses using ROC. RESULTS: cfDNA concentration in advanced GC patients was significantly higher than that in healthy controls (P<0.05). The concentration of plasma cfDNA in patients with PD showed an increasing trend over time. The concentration of plasma cfDNA in patients with therapeutic effect of PR decreased over time. In patients with therapeutic effect of SD, the plasma DNA concentration showed a stable trend over time. There was no significant correlation between cfDNA concentration and factors including gender, age, pathological type, CA724, CA125,CA199, AFP and CEA. ROC results showed that the area under the curve of cfDNA was larger than other tumor markers. CONCLUSION: Plasma cfDNA concentration was significantly increased in patients with gastric cancer, and its diagnostic efficacy was superior to that of traditional tumor markers. It can be used as a tumor biomarker to monitor the efficacy of chemotherapy for gastric cancer.