Dr Kasi on the Use of ctDNA to Help Inform Adjuvant Treatment Decisions in CRC

Pashtoon Murtaza Kasi, MD, MS, oncologist and researcher, Weill Cornell Medicine and NewYork-Presbyterian Hospital, discussess the propensity for over-treatment in the adjuvant setting across various cancers, including colorectal cancer (CRC), and the potential to use circulating tumor DNA (ctDNA) to inform treatment decision-making in this setting.

He highlights the challenge of accurately discerning patients who are cured following surgery vs those who may require further aggressive therapy. Presently, treatment decisions rely heavily on static variables derived from the final pathology reports post-surgery, Kasi notes.

Kasi suggests that liquid biopsies to measure ctDNA offer a promising avenue to address this challenge. Specifically, ctDNA positivity indicates persistence of disease, indicative of patients who have not achieved cure post-surgery, which may necessitate additional therapy. Beyond its prognostic and predictive value, ctDNA serves as a marker for residual disease, guiding further treatment decisions in the adjuvant setting, he explains.

Traditionally, clinicians have made treatment decisions without a precise marker to ascertain a patient's curative status following surgery. However, the continued evolution of ctDNA testing could allow for a more nuanced understanding of a patient’s response to therapy. Notably, ctDNA detection can elucidate micro-responses to treatment; for example, clearance of ctDNA could indicate a favorable response to therapy, Kasi says.

Kasi emphasizes that ctDNA testing represents a valuable tool in the adjuvant setting, offering insights into a patient's curative status and response to therapy. By identifying residual disease and micro-responses to treatment, ctDNA testing facilitates more informed and personalized treatment decisions for patients with CRC and potentially other malignancies, he concludes.