The INTERCEPT CRC study showed that clearing circulating tumor DNA (ctDNA) after adjuvant therapy is a powerful indicator of better outcomes in patients with resectable stage I–IV colorectal cancer. Researchers found that among patients who were ctDNA-positive after surgery, 26% achieved ctDNA clearance following adjuvant treatment. These patients had significantly longer disease-free survival compared to those who remained ctDNA-positive, a benefit observed in both early-stage (I–III) and advanced-stage (IV) disease (P < .0001).
After surgery, most patients (69%) consistently tested negative for ctDNA, while 18% remained positive across all tests. Once adjuvant therapy was completed, 70% of patients had negative ctDNA results throughout follow-up, and 19% stayed positive, suggesting treatment effectively eliminated minimal residual disease in many cases.
Spontaneous ctDNA clearance without therapy was extremely uncommon. Only 2.1% of patients who ever tested positive showed a sustained negative result without intervention, and this temporary clearance lasted a median of 11.2 months.
Overall, the study confirms that ctDNA clearance after adjuvant therapy is a meaningful marker of treatment success, reflecting the eradication of microscopic disease and predicting a much lower risk of recurrence.