As precision oncology evolves, circulating tumor DNA is gaining recognition for its role in personalized cancer treatment. By monitoring molecular residual disease, ctDNA testing offers oncologists a way to detect and track cancer at a molecular level, enabling more precise assessment and potential for more individualized care. For oncology service lines within health systems, integrating ctDNA-based MRD testing may improve care quality and improve patient outcomes. However, challenges and key questions still need to be addressed for successful adoption.
Traditional imaging tools like CT and PET scans, though valuable, have limitations in detecting early cancer recurrence. These methods are less sensitive to low levels of molecular residual disease, allowing low levels of tumor burden to progress undetected. Circulating tumor DNA-based MRD testing offers oncologists a more sensitive way to detect recurrence earlier, enabling timely treatment decisions.
One key opportunity for MRD testing is guiding adjuvant therapy decisions. After primary treatments like surgery or neoadjuvant chemotherapy, oncologists must decide if additional therapy is needed to prevent recurrence. Circulating tumor DNA testing can detect traces of tumor-derived genetic material, indicating the presence of MRD, helping clinicians avoid overtreatment or under-treatment. The MRD is present, adjuvant therapy can be pursued; if it is absent, patients may be spared unnecessary treatment, reducing side effects, and potentially improving outcomes.
Despite the promise of circulating tumor DNA-based MRD testing, questions remain about its optimal use, and these uncertainties can cause hesitancy among clinicians and payers. While clinical validation data are maturing in colorectal cancer, there remains a lack of guideline recommendations for MRD testing in CRC. In other common solid cancer types MRD evidence is less developed and providers remain cautious, unsure whether MRD should be routine for all cancer patients or limited to high-risk cases.
This hesitation among clinicians contributes to a broader issue: payers may be reluctant to cover MRD testing without definitive guidelines, leading to disparities in patient access. As a result, potentially eligible patients—those who could benefit most from early detection and intervention—may be left without the option of MRD testing. This delay in widespread adoption of MRD testing leaves room for continued cancer recurrence that could otherwise be detected earlier where clinicians can make more rapid decisions.
For health systems, ctDNA-based MRD testing could significantly improve the quality of oncology care. By enabling earlier detection of cancer recurrence, MRD testing can help oncologists to make more informed and timely clinical decisions. Moreover, MRD testing may reduce the need for invasive biopsies for recurrence monitoring. A simple blood draw can provide the necessary information (the presence or lack of ctDNA), improve the patient experience and reduce the risks associated with traditional biopsy procedures. This patient-centered approach is especially important in oncology, where treatments are often invasive and lengthy.
The ability to detect recurrence earlier may potentially impact outcomes, particularly in colorectal cancer, the third most common cancer globally. Despite advancements in surgery and therapy, recurrence remains a challenge. Circulating tumor DNA-based MRD testing allows monitoring of residual cancer cells after treatment, providing oncologists with the chance to intervene before visible signs appear on imaging.
In patients who have undergone surgery or chemotherapy, ctDNA can reveal whether cancerous cells remain, which can help providers determine whether additional treatment is necessary, or potentially help spare patients from unnecessary therapies when no ctDNA is detected. This proactive approach may help improve survival outcomes and enhance quality of life by preventing overtreatment. The impact extends to other cancers, where ctDNA can help enable tailored treatments, for more effective and timely care.
While the benefits of ctDNA-based MRD testing are clear, adopting it poses challenges for health systems. One of the primary considerations is cost. Although ctDNA testing offers valuable insights, health systems must weigh its costs against other diagnostic tools and resources. Additionally, implementing MRD testing requires investment in infrastructure, lab capabilities, and clinician training to ensure accurate interpretation of results.
Workflow integration is another factor. MRD testing needs to be seamlessly incorporated into oncology protocols, requiring interdisciplinary teams and clear communication with patients about their results and next steps.
Incorporating ctDNA-based MRD testing into oncology service lines presents a significant opportunity to enhance cancer care in the era of precision medicine. By offering recurrence monitoring which supports more personalized treatment plans, it has the potential to improve both care quality and patient outcomes. Health systems that adopt this innovative technology can elevate their standard of care, reduce unnecessary treatments, and may help improve survival rates, making MRD testing a transformative tool in modern oncology.
Rick Baehner, MD, is CMO, Precision Oncology, Exact Sciences.
A Premier Corporate Partner of ACHE, Exact Sciences relentlessly pursues smarter solutions providing the clarity to take life-changing action, earlier. For more information, go to ache.org/ExactSciences.