The diagnostic and prognostic usage of circulating tumor DNA in operable hepatocellular carcinoma

Circulating tumor DNA (ctDNA) is a promising noninvasive biomarker for hepatocellular carcinoma (HCC). In this study, we aimed to assess the diagnostic and prognostic value of ctDNA in HCC. Twenty-six operable HCC, 10 hepatitis and 10 cirrhosis patients were enrolled in this study. Treatment-naive blood samples were collected from all patients, nevertheless resected tissue and postoperative blood samples were only collected from HCC patients. A custom-designed sequencing panel covering 354 genes was used to identify somatic mutations. Collectively, we identified 139 somatic mutations from 25 HCC baseline plasma samples (96.2%). TP53 (50.00%) was the most common mutant gene, and R249S was the most recurrent mutation (19.2%). Twenty-three patients (88.5%) carried at least one ctDNA mutation validated in matched tissue, and the driver mutations exhibited an advanced concordance than non-driver mutations (67.6% vs. 33.8%, P= 0.0002). For HCC patients, the number of mutations in ctDNA (R-2 = 0.1682, P = 0.0375), maximal variant allele frequency (VAF) in ctDNA (R-2 = 0.4974, P < 0.0001) and ctDNA concentration (R-2 = 0.2676, P = 0.0068) were linearly correlated with tumor size. Multiple circulating cell-free DNA (cfDNA) parameters could be used in differentiating malignant lesions from benign lesions, and the performance was no less than blood alpha-fetoprotein (AFP). HCC patients with detectable mutation in postoperative plasma had a poor DFS than those without (17.5 months vs. 6.7 months, HR = 7.655, P < 0.0001), and postoperative cfDNA status (HR = 10.293, P < 0.0001) was an independent risk factors for recurrence. In conclusion, ctDNA profiling is potentially valuable in differential diagnosis and prognostic evaluation of HCC.