Dynamic Circulating Tumor DNA Methylation Monitoring Guiding Postoperative Surveillance in Nonmetastatic Colorectal Cancer: A Prospective, Randomized, Phase III FIND Trial

PURPOSE We hypothesized that a dynamic surveillance strategy guided by circulating tumor DNA (ctDNA) methylation would increase the rate of curative-intent therapy for recurrence in patients with nonmetastatic colorectal cancer (CRC) after curative resection. METHODS The FIND trial (ClinicalTrials.gov identifier: NCT05904665 ) is a prospective, multicenter, randomized, phase III study. Patients with nonmetastatic CRC were randomly assigned to ctDNA-guided surveillance or standard computed tomography (CT)–based monitoring. In the ctDNA-guided group, a positive ctDNA result triggered immediate CT imaging; if negative, bimonthly CT continued alongside quarterly ctDNA testing. After two consecutive ctDNA-negative results, imaging reverted to standard frequency. The primary end point was the proportion of patients with recurrence receiving curative-intent metastasis-directed therapy. RESULTS Among 584 eligible patients (289 ctDNA-guided, 295 control) in the modified intention-to-treat population, with a median follow-up of 23.3 months, recurrence rates were similar (18.0% v 18.6%, P = .919). The ctDNA-guided group had a significantly higher rate of curative-intent treatment (48.1% v 23.6%, relative risk 2.03, P = .008). The median time to clinical recurrence was significantly shorter in the ctDNA-guided group than in the control group (9.5 v 13.4 months; P < .001), representing a lead time of 3.9 months. Among recurrences confined to the liver and/or lungs, the ctDNA-guided group showed higher curative resection rates (42.3% v 18.2%, P = .002). These patients had more favorable hepatic metastatic features: fewer lesions (≤3: 75.0% v 28.6%, P = .005), smaller tumor size (≤3 cm: 90.0% v 57.1%, P = .033), and more unilobar disease (80.0% v 28.6%, P = .002). CONCLUSION ctDNA methylation-guided dynamic surveillance improves the rate of curative-intent therapy for recurrence in patients with initially nonmetastatic CRC through earlier detection of resectable metastases, pending validation of long-term survival benefit in future analyses with mature data.