ctDNA Assessment in Characterizing Recurrence Sites after Resection for Metastatic Colorectal Cancer

Among 31 patients who underwent optimal resection for metastatic colorectal cancer (mCRC), circulating tumor DNA (ctDNA) was detected in 83.4% of those who experienced postoperative recurrence, while remaining undetectable in those without recurrence. ctDNA was detected earlier than clinical diagnosis by a median of nine weeks, and its levels were significantly lower in peritoneal-only recurrence compared to distant recurrence. These findings suggest that ctDNA testing can effectively characterize recurrence sites after resection for mCRC, aiding in the development of targeted treatments specific to the involved sites.