Dr Emerik Österlund talks to ecancer at ESMO 2025 about the INTERCEPT study he presented data from.

This investigated circulating tumour DNA (ctDNA) clearance after curative-intent procedures in 1,301 colorectal cancer (CRC) patients to understand behaviour, frequency, and relationship with outcomes.

Most patients (69%) remained ctDNA-negative after surgery. Among those who were ctDNA-positive, only a small proportion achieved clearance, and durable spontaneous ctDNA clearance was rare (≈1.7%). Some ctDNA clearance occurred during adjuvant therapy, but spontaneous clearance without treatment was uncommon and typically involved low ctDNA levels.

Patients with persistent ctDNA clearance had the longest disease-free survival (DFS), while those with persistent or newly positive ctDNA had the shortest DFS, confirming ctDNA’s strong prognostic value.

Dr Österlund notes that ctDNA clearance, especially when durable, is uncommon but associated with better outcomes. While adjuvant therapy can induce ctDNA clearance, spontaneous clearance is rare. Therefore, ctDNA clearance may serve as a potential surrogate marker for treatment efficacy, though it is not sufficient alone to indicate clinical benefit.