Abstract: Objective To explore theapplicationvalue of combined detection of peripheral blood circulating tumor cells （CTCs） and cell-free DNA （cfDNA） in earlyscreening of liver cancer. Methods From September 2017 to August 2019, a total of one hundred and eighty-twohighly suspected liver cancer patients were enrolled in this study, who were divided into cancer group and benign group according to pathological results.T-testwas used for the difference of clinical data and CTCs/cfDNA. Pearson correlation analysis was employed to analyze the relationship between CTCs, cfDNA levels and liver function indexes and related tumor markers in cancer group. Receiver working characteristic （ROC）curves were used to evaluate diagnostic efficacy of CTCs and cfDNA detection in early liver cancer screening. Results The levels of AFP, γ- GT, CEA, ALT, AST, GGT, ALP and peripheral blood CTCs and cfDNA in cancer group were higher than benign group（P<0.05）.Pearson correlation analysis showed that the levels of CTCs and cfDNA were positively correlated with AFP, CEA and liver function（P<0.05）.There were significant difference between peripheral blood CTCs and cfDNA among different stages of liver cancer（P<0.05）. The ROC analysis showed that AUC of CTCsfor diagnosis of liver cance was 0.854, with cut-off 4 CTCs/5ml, with sensitivity and specificity was 75.54% and 86.05%, respectively; and that AUC of cfDNA was 0.831, with cut-off 19.38ng/ml, with sensitivity and specificity was 78.42% and 79.07%, respectively;butAUC, sensitivity and specificity of both indexsin the diagnosis of liver cancer were 0.923, 82.01% and 90.70%respectively. Conclusion The levels of CTCs and cfDNA in peripheral blood of patients with liver cancer are increased. The combined detection of CTCs and cfDNA has higher clinical value for early screening of liver cancer.

Key words: Circulating, tumor, cells, Cell-free, DNA, Liver, cancer, Screening, value