Analysis of colorectal cancer‐related mutations by liquid biopsy: Utility of circulating cell‐free DNA and circulating tumor cells

摘要

We recruited 56 colorectal cancer patients and compared the mutational spectrum of tumor tissue , circulating cell‐free (ccf ) and circulating tumor cell ( ) (ctc ) to evaluate the potential of liquid biopsy to detect heterogeneity of cancer. Tumor tissue , ccf , and ctc were extracted from each patient and analyzed using next‐generation sequencing ( ) and digital . To maximize yields of , three antibodies were used in the capture process. From 34 untreated patients, 53 mutations were detected in tumor tissue using . Forty‐seven mutations were detected in ccf , including 20 not detected in tissues. Sixteen mutations were detected in ctc , including five not detected in tissues. In 12 patients (35.3%), mutations not found in tumor tissues were detected by liquid biopsy: nine (26.5%) in ccf only and three (8.8%) in ctc only. Combination analysis of the two liquid biopsy samples increased the sensitivity to detect heterogeneity. From 22 stage patients with mutations in their primary tumors, mutations were detected in 14 (63.6%) ccf and in eight (36.4%) ctc using digital . Mutations not detected in primary tumors can be identified in ccf and in ctc , indicating the potential of liquid biopsy in complementing gene analysis. Combination analysis improves sensitivity. Sensitivity to detect cancer‐specific mutations is higher in ccf compared with ctc .