Liquid biopsies for minimal residual disease detection after resection of stage I to III colorectal cancer

The absence of postoperative circulating tumor DNA (ctDNA) identifies patients with resected colorectal cancer (CRC) with low recurrence risk, who could be candidates for adjuvant chemotherapy de-escalation. The UK TRACC Part B study analyzed 997 plasma samples from 214 patients after resection for stage I to III CRC. Two-year RFS was 91.1% with ctDNA not detected postoperatively and 50.4% in those with ctDNA detected (HR 6.5; p<0.001). The median lead time from ctDNA detection to radiologic recurrence was 7.3 months (IQR 3.3-12.5). The authors conclude that ctDNA detection in postoperative liquid biopsies predicts recurrence in patients with stage I to III CRC. UK TRACC Part C is currently investigation the potential for adjuvant chemotherapy de-escalation in patient with undetectable postoperative ctDNA.