He Y, Ma X, Chen K, et al. - Given surgical resection has been confirmed as the most crucial modality for long-term survival in colorectal cancer with liver metastases (CLM) but there is a lack of effective biomarkers for outcome prediction or postoperative surveillance, and therefore, researchers performed this study with patients with CLM in order to assess the worth of the liquid biopsy, which involves circulating tumor DNA (ctDNA) and cell-free DNA (cfDNA), in this patient population. Participants were 20 CRC patients who had the resection of liver metastases between May and September 2017. Capture-based targeted deep sequencing was done on matched pre-surgery, post-surgery and liver metastatic tissues of participants, employing a panel comprising 41 genes. Overall, 47 mutations were found from 17 pre-surgery plasma samples (85%), and the rest of the 3 patients demonstrated no mutation detected from the panel. A high by-variant concordance rate of 82.14% was identified between pre-surgery plasma samples and liver metastatic tissue samples. Experts found that the genomic profile obtained from ctDNA vs that obtained from metastatic liver tumors was comparable. A positive correlation of pre-surgery ctDNA levels with tumor burden was also revealed. Predictive value for relapse was shown by pre-surgery ctDNA, cfDNA and CEA levels.