Evaluating the Clinical Value of ctDNA Testing in the Longitudinal Management of the CRC Patient
Experts discuss the expanding role of ctDNA as a prognostic and predictive tool in colorectal cancer management, emphasizing its ability to personalize postoperative surveillance and treatment decisions—particularly in ambiguous clinical scenarios—while highlighting the need for sensitive assays and thoughtful communication around emotionally challenging results.
Circulating tumor DNA (ctDNA) has rapidly evolved into a valuable prognostic tool in colorectal cancer management, particularly after surgical resection. While Although a positive result strongly correlates with a high risk of recurrence, a negative result—especially when serially confirmed over time—provides meaningful reassurance. However, this reassurance is not absolute, as ctDNA-negative patients may still experience recurrence. Importantly, ctDNA’s reliability varies by platform, and tumor-informed assays, which tailor the test to the patient’s own tumor mutations, have demonstrated superior sensitivity. These assays can even detect molecular relapse months before it becomes radiologically or clinically evident, influencing earlier therapeutic intervention.
Despite the clear prognostic power, the emotional weight of a positive result—especially when imaging and other markers remain normal—can lead to anxiety for patients. This underscores the need for clinicians to have structured communication and follow-up plans in place when using these tests. In practice, ctDNA is being used across disease stages II to IV in many institutions, not only to assess residual disease postoperatively, but also to guide chemotherapy decisions and inform management strategies in the neoadjuvant and adjuvant settings. In particular, for patients with resected Stage stage IV disease or high-risk Stage stage III patientsdisease, ctDNA can help determine whether further systemic treatment is warranted.
In certain settings, ctDNA is proving especially useful where clinical ambiguity exists—such as in Stage patients with stage II (T3N0) patientsdisease, where the benefit of adjuvant chemotherapy is debated. Here, ctDNA can help personalize decisions, potentially sparing low-risk patients from unnecessary treatment. While Although it may not yet be universally adopted in every institution or stage, its role as both a prognostic and predictive marker continues to expand. As data accumulates, ctDNA is increasingly integrated into surveillance protocols and decision-making algorithms, ultimately aiming to optimize outcomes while minimizing overtreatment.
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