Efficacy of circulating tumour DNA in guiding postoperative adjuvant chemotherapy for resectable colorectal cancer: A meta-analysis based on cohort studies.

The value of circulating tumour DNA (ctDNA) in resectable colorectal cancer (CRC) remains unclear. The present study evaluated the efficacy of ctDNA-guided adjuvant chemotherapy (ACT) in patients with resectable CRC after surgery. A systematic search was conducted in PubMed, Web of Science, EMBASE and the Cochrane Library databases for relevant studies published from January 2010 to July 2026. The inclusion criteria were studies that: i) Included patients with resectable CRC who underwent postoperative ctDNA testing before ACT initiation; ii) stratified the assessment of ACT efficacy based on ctDNA test results; and iii) reported recurrence-free survival (RFS) and/or overall survival (OS). The hazard ratio (HR) and 95% confidence interval (CI) were used to evaluate the results. The meta-analysis included 4 cohort studies and 1 randomized controlled trial, involving 2,081 evaluable patients with resectable CRC (441 cases in the ctDNA-positive group and 1,640 cases in the ctDNA negative group). Among the patients positive for ctDNA, the RFS rate (HR, 0.34; 95% CI, 0.16-0.73; P=0.006) and OS rate (HR, 0.40; 95% CI, 0.20-0.81; P=0.01) of the group that received ACT were significantly improved compared with those in patients who did not receive ACT. Among the patients negative for ctDNA, there was no statistically significant difference in the RFS rate (HR, 1.05; 95% CI, 0.70-1.60; P=0.802) and OS rate (HR, 0.66; 95% CI, 0.28-1.56; P=0.348) between the ACT and non-ACT groups. Therefore, the present study revealed that ctDNA testing may serve as a marker for guiding ACT in patients with resectable CRC after surgery.